1e27ed2014-09-04Henrik Grubbström (Grubba) News for the tz database
b401d62018-12-18Henrik Grubbström (Grubba) Release 2018g - 2018-10-26 22:22:45 -0700 Briefly: Morocco switches to permanent +01 on 2018-10-27. Changes to future timestamps Morocco switches from +00/+01 to permanent +01 effective 2018-10-27, so its clocks will not fall back on 2018-10-28 as previously scheduled. (Thanks to Mohamed Essedik Najd and Brian Inglis.) Changes to code When generating TZif files with leap seconds, zic no longer uses a format that trips up older 32-bit clients, fixing a bug introduced in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround for QTBUG-53071 now also works for TZif files with leap seconds. The translator to rearguard format now rewrites the line "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S". This caters to zic before 2007 and to Oracle TZUpdater 2.2.0 and earlier. (Reported by Christos Zoulas.) Changes to past time zone abbreviations Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii. This reverts to 2011h, as the abbreviation change in 2011i was likely inadvertent. Changes to documentation tzfile.5 has new sections on interoperability issues. Release 2018f - 2018-10-18 00:14:18 -0700 Briefly: Volgograd moves from +03 to +04 on 2018-10-28. Fiji ends DST 2019-01-13, not 2019-01-20. Most of Chile changes DST dates, effective 2019-04-06. Changes to future timestamps Volgograd moves from +03 to +04 on 2018-10-28 at 02:00. (Thanks to Alexander Fetisov and Stepan Golosunov.) Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously predicted. (Thanks to Raymond Kumar.) Adjust future predictions accordingly. Most of Chile will end DST on the first Saturday in April at 24:00 mainland time, and resume DST on the first Saturday in September at 24:00 mainland time. The changes are effective from 2019-04-06, and do not affect the Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa and Tim Parenti.) Adjust future predictions accordingly. Changes to past timestamps The 2018-05-05 North Korea 30-minute time zone change took place at 23:30 the previous day, not at 00:00 that day. China's 1988 spring-forward transition was on April 17, not April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00. (Thanks to P Chan.) Fix several issues for Macau before 1992. Macau's pre-1904 LMT was off by 10 s. Macau switched to +08 in 1904 not 1912, and temporarily switched to +09/+10 during World War II. Macau observed DST in 1942/79, not 1961/80, and there were several errors for transition times and dates. (Thanks to P Chan.) The 1948-1951 fallback transitions in Japan were at 25:00 on September's second Saturday, not at 24:00. (Thanks to Phake Nick.) zic turns this into 01:00 on the day after September's second Saturday, which is the best that POSIX or C platforms can do. Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014 paper by Li Yu, replacing more-questionable data from Shanks. Changes to time zone abbreviations Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.) Changes to code zic now always generates TZif files where time type 0 is used for timestamps before the first transition. This simplifies the reading of TZif files and should not affect behavior of existing TZif readers because the same set of time types is used; only their internal indexes may have changed. This affects only the legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and EET, which previously used nonzero types for these timestamps. Because of the type 0 change, zic no longer outputs a dummy transition at time -2**59 (before the Big Bang), as clients should no longer need this to handle historical timestamps correctly. This reverts a change introduced in 2013d and shrinks most TZif files by a few bytes. zic now supports negative time-of-day in Rule and Leap lines, e.g., "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition occurs at 18:00 on the Saturday before the last Sunday in April. This behavior was documented in 2018a but the code did not entirely match the documentation. localtime.c no longer requires at least one time type in TZif files that lack transitions or have a POSIX-style TZ string. This future-proofs the code against possible future extensions to the format that would allow TZif files with POSIX-style TZ strings and without transitions or time types. A read-access subscript error in localtime.c has been fixed. It could occur only in TZif files with timecnt == 0, something that does not happen in practice now but could happen in future versions. localtime.c no longer ignores TZif POSIX-style TZ strings that specify only standard time. Instead, these TZ strings now override the default time type for timestamps after the last transition (or for all time stamps if there are no transitions), just as DST strings specifying DST have always done. leapseconds.awk now outputs "#updated" and "#expires" comments, and supports leap seconds at the ends of months other than June and December. (Inspired by suggestions from Chris Woodbury.) Changes to documentation New restrictions: A Rule name must start with a character that is neither an ASCII digit nor "-" nor "+", and an unquoted name should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~". The latter restriction makes room for future extensions (a possibility noted by Tom Lane). tzfile.5 now documents what time types apply before the first and after the last transition, if any. Documentation now uses the spelling "timezone" for a TZ setting that determines timestamp history, and "time zone" for a geographic region currently sharing the same standard time. The name "TZif" is now used for the tz binary data format. tz-link.htm now mentions the A0 TimeZone Migration utilities. (Thanks to Aldrin Martoq for the link.) Changes to build procedure New 'make' target 'rearguard_tarballs' to build the rearguard tarball only. This is a convenience on platforms that lack lzip if you want to build the rearguard tarball. (Problem reported by Deborah Goldsmith.) tzdata.zi is now more stable from release to release. (Problem noted by Tom Lane.) It is also a bit shorter. tzdata.zi now can contain comment lines documenting configuration information, such as which data format was selected, which input files were used, and how leap seconds are treated. (Problems noted by Lester Caine and Brian Inglis.) If the Makefile defaults are used these comment lines are absent, for backward compatibility. A redistributor intending to alter its copy of the files should also append "-LABEL" to the 'version' file's first line, where "LABEL" identifies the redistributor's change.
07968a2018-09-05Henrik Grubbström (Grubba) Release 2018e - 2018-05-01 23:42:51 -0700 Briefly: North Korea switches back to +09 on 2018-05-05. The main format uses negative DST again, for Ireland etc. 'make tarballs' now also builds a rearguard tarball. New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  North Korea switches back from +0830 to +09 on 2018-05-05. (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon, and Tim Parenti.) Bring back the negative-DST changes of 2018a, except be more compatible with data parsers that do not support negative DST.
b401d62018-12-18Henrik Grubbström (Grubba)  Also, this now affects historical timestamps in Namibia and the
07968a2018-09-05Henrik Grubbström (Grubba)  former Czechoslovakia, not just Ireland. The main format now uses
b401d62018-12-18Henrik Grubbström (Grubba)  negative DST to model timestamps in Europe/Dublin (from 1971 on),
07968a2018-09-05Henrik Grubbström (Grubba)  Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This does not affect UT offsets, only time zone abbreviations and the tm_isdst flag. Also, this does not affect rearguard or vanguard formats; effectively the main format now uses vanguard instead of rearguard format. Data parsers that do not support negative DST can still use data from the rearguard tarball described below. Changes to build procedure The command 'make tarballs' now also builds the tarball tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz except that it uses rearguard format intended for trailing-edge data parsers. Changes to data format and to code The SAVE column of Rule and Zone lines can now have an 's' or 'd' suffix, which specifies whether the adjusted time is standard time or daylight saving time. If no suffix is given, daylight saving time is used if and only if the SAVE column is nonzero; this is the longstanding behavior. Although this new feature is not used in tzdata, it could be used to specify the legal time in Namibia 1994-2017, as opposed to the popular time (see below).
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  From 1994 through 2017 Namibia observed DST in winter, not summer. That is, it used negative DST, as Ireland still does. This change does not affect UTC offsets; it affects only the tm_isdst flag and the abbreviation used during summer, which is now CAT, not WAST. Although (as noted by Michael Deckers) summer and winter time were both simply called "standard time" in Namibian law, in common practice winter time was considered to be DST (as noted by Stephen Colebourne). The full effect of this change is only in vanguard
b401d62018-12-18Henrik Grubbström (Grubba)  and main format; in rearguard format, the tm_isdst flag is still
07968a2018-09-05Henrik Grubbström (Grubba)  zero in winter and nonzero in summer. In 1946/7 Czechoslovakia also observed negative DST in winter.
b401d62018-12-18Henrik Grubbström (Grubba)  The full effect of this change is only in vanguard and main formats; in rearguard format, it is modeled as plain GMT without
07968a2018-09-05Henrik Grubbström (Grubba)  daylight saving. Also, the dates of some 1944/5 DST transitions in Czechoslovakia have been changed. Release 2018d - 2018-03-22 07:05:46 -0700 Briefly: Palestine starts DST a week earlier in 2018. Add support for vanguard and rearguard data consumers. Add subsecond precision to source data format, though not to data.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  In 2018, Palestine starts DST on March 24, not March 31. Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  Casey Station in Antarctica changed from +11 to +08 on 2018-03-11 at 04:00. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  Historical transitions for Uruguay, represented by America/Montevideo, have been updated per official legal documents, replacing previous data mainly originating from the inventions of Shanks & Pottenger. This has resulted in adjustments ranging from 30 to 90 minutes in either direction over at least two dozen distinct periods ranging from one day to several years in length. A mere handful of pre-1991 transitions are unaffected; data since then has come from more reliable contemporaneous reporting. These changes affect various timestamps in 1920-1923, 1936, 1939, 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990. Additionally, Uruguay's pre-standard-time UT offset has been adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to match the location of the Observatory of the National Meteorological Institute in Montevideo. (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.) Enderbury and Kiritimati skipped New Year's Eve 1994, not New Year's Day 1995. (Thanks to Kerry Shetline.) Fix the 1912-01-01 transition for Portugal and its colonies. This transition was at 00:00 according to the new UT offset, not according to the old one. Also assume that Cape Verde switched on the same date as the rest, not in 1907. This affects Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores, Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon. (Thanks to Michael Deckers.) Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in Turks & Caicos. Changes to past time zone abbreviations MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There is no clock change associated with the transition. Changes to build procedure The new DATAFORM macro in the Makefile lets the installer choose among three source data formats. The idea is to lessen downstream disruption when data formats are improved. * DATAFORM=vanguard installs from the latest, bleeding-edge format. DATAFORM=main (the default) installs from the format used in the 'africa' etc. files. DATAFORM=rearguard installs from a trailing-edge format. Eventually, elements of today's vanguard format should move to the main format, and similarly the main format's features should eventually move to the rearguard format. * In the current version, the main and rearguard formats are identical and match that of 2018c, so this change does not affect default behavior. The vanguard format currently contains one feature not in the main format: negative SAVE values. This improves support for Ireland, which uses Irish Standard Time (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has supported negative SAVE values for decades, and this feature should move to the main format soon. However, it will not move to the rearguard format for quite some time because some downstream parsers do not support it. * The build procedure constructs three files vanguard.zi, main.zi, and rearguard.zi, one for each format. The files represent the same data as closely as the formats allow. These three files are intended for downstream data consumers and are not installed. Zoneinfo parsers that do not support negative SAVE values should start using rearguard.zi, so that they will be unaffected when the negative-DST feature moves from vanguard to main. Bleeding-edge Zoneinfo parsers that support the new features already can use vanguard.zi; in this respect, current tzcode is bleeding-edge. The Makefile should now be safe for parallelized builds, and 'make -j to2050new.tzs' is now much faster on a multiprocessor host with GNU Make. When built with -DSUPPRESS_TZDIR, the tzcode library no longer prepends TZDIR/ to file names that do not begin with '/'. This is not recommended for general use, due to its security implications. (From a suggestion by Manuela Friedrich.) Changes to code zic now accepts subsecond precision in expressions like 00:19:32.13, which is approximately the legal time of the Netherlands from 1835 to 1937. However, because it is questionable whether the few recorded uses of non-integer offsets had subsecond precision in practice, there are no plans for tzdata to use this feature. (Thanks to Steve Allen for pointing out the limitations of historical data in this area.) The code is a bit more portable to MS-Windows. Installers can compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that reserve identifiers like 'localtime'. (Thanks to Manuela Friedrich). Changes to documentation and commentary theory.html now outlines tzdb's extensions to POSIX's model for civil time, and has a section "POSIX features no longer needed" that lists POSIX API components that are now vestigial. (From suggestions by Steve Summit.) It also better distinguishes time zones from tz regions. (From a suggestion by Guy Harris.) Commentary is now more consistent about using the phrase "daylight saving time", to match the C name tm_isdst. Daylight saving time need not occur in summer, and need not have a positive offset from standard time. Commentary about historical transitions in Uruguay has been expanded with links to many relevant legal documents. (Thanks to Tim Parenti.) Commentary now uses some non-ASCII characters with Unicode value less than U+0100, as they can be useful and should work even with older editors such as XEmacs. Release 2018c - 2018-01-22 23:00:44 -0800 Briefly: Revert Irish changes that relied on negative SAVE values. Changes to tm_isdst Revert the 2018a change to Europe/Dublin. As before, this change does not affect UT offsets or abbreviations; it affects only whether timestamps are considered to be standard time or daylight-saving time, as expressed in the tm_isdst flag of C's struct tm type. This reversion is intended to be a temporary workaround for problems discovered with downstream uses of releases 2018a and 2018b, which implemented Irish time by using negative SAVE values in the Eire rules of the 'europe' file. Although negative SAVE values have been part of tzcode for many years and are supported by many platforms, they were not documented before 2018a and ICU and OpenJDK do not currently support them. A mechanism to export data to platforms lacking support for negative DST is planned to be developed before the change is reapplied. (Problems reported by Deborah Goldsmith and Stephen Colebourne.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  Japanese DST transitions (1948-1951) were Sundays at 00:00, not Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.) Changes to build procedure The build procedure now works around mawk 1.3.3's lack of support for character class expressions. (Problem reported by Ohyama.) Release 2018b - 2018-01-17 23:24:48 -0800 Briefly: Fix a packaging problem in tz2018a, which was missing 'pacificnew'. Changes to build procedure The distribution now contains the file 'pacificnew' again. This file was inadvertantly omitted in the 2018a distribution. (Problem reported by Matias Fonzo.) Release 2018a - 2018-01-12 22:29:21 -0800 Briefly: São Tomé and Príncipe switched from +00 to +01. Brazil's DST will now start on November's first Sunday. Ireland's standard time is now in the summer, not the winter. Use Debian-style installation locations, instead of 4.3BSD-style. New zic option -t.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  Starting in 2018 southern Brazil will begin DST on November's first Sunday instead of October's third Sunday. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
07968a2018-09-05Henrik Grubbström (Grubba)  A discrepancy of 4 s in timestamps before 1931 in South Sudan has been corrected. The 'backzone' and 'zone.tab' files did not agree with the 'africa' and 'zone1970.tab' files. (Problem reported by Michael Deckers.) The abbreviation invented for Bolivia Summer Time (1931-2) is now BST instead of BOST, to be more consistent with the convention used for Latvian Summer Time (1918-9) and for British Summer Time. Changes to tm_isdst Change Europe/Dublin so that it observes Irish Standard Time (UT +01) in summer and GMT (as negative daylight-saving) in winter, instead of observing standard time (GMT) in winter and Irish Summer Time (UT +01) in summer. This change does not affect UT offsets or abbreviations; it affects only whether timestamps are considered to be standard time or daylight-saving time, as expressed in the tm_isdst flag of C's struct tm type. (Discrepancy noted by Derick Rethans.) Changes to build procedure The default installation locations have been changed to mostly match Debian circa 2017, instead of being designed as an add-on to 4.3BSD circa 1986. This affects the Makefile macros TOPDIR, TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR, USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor locations more precisely. (This responds to suggestions from Brian Inglis and from Steve Summit.) The default installation procedure no longer creates the backward-compatibility link US/Pacific-New, which causes confusion during user setup (e.g., see Debian bug 815200). Use 'make BACKWARD="backward pacificnew"' to create the link anyway, for now. Eventually we plan to remove the link entirely. tzdata.zi now contains a version-number comment. (Suggested by Tom Lane.) The Makefile now quotes values like BACKWARD more carefully when passing them to the shell. (Problem reported by Zefram.) Builders no longer need to specify -DHAVE_SNPRINTF on platforms that have snprintf and use pre-C99 compilers. (Problem reported by Jon Skeet.) Changes to code zic has a new option -t FILE that specifies the location of the file that determines local time when TZ is unset. The default for this location can be configured via the new TZDEFAULT makefile macro, which defaults to /etc/localtime. Diagnostics and commentary now distinguish UT from UTC more carefully; see theory.html for more information about UT vs UTC. zic has been ported to GCC 8's -Wstringop-truncation option. (Problem reported by Martin Sebor.) Changes to documentation and commentary The zic man page now documents the longstanding behavior that times and years can be out of the usual range, with negative times counting backwards from midnight and with year 0 preceding year 1. (Problem reported by Michael Deckers.) The theory.html file now mentions the POSIX limit of six chars per abbreviation, and lists alphabetic abbreviations used. The files tz-art.htm and tz-link.htm have been renamed to tz-art.html and tz-link.html, respectively, for consistency with other file names and to simplify web server configuration.
8de8e92017-11-17Henrik Grubbström (Grubba) Release 2017c - 2017-10-20 14:49:34 -0700 Briefly: Northern Cyprus switches from +03 to +02/+03 on 2017-10-29. Fiji ends DST 2018-01-14, not 2018-01-21. Namibia switches from +01/+02 to +02 on 2018-04-01. Sudan switches from +03 to +02 on 2017-11-01. Tonga likely switches from +13/+14 to +13 on 2017-11-05. Turks & Caicos switches from -04 to -05/-04 on 2018-11-04. A new file tzdata.zi now holds a small text copy of all data. The zic input format has been regularized slightly.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
8de8e92017-11-17Henrik Grubbström (Grubba)  Northern Cyprus has decided to resume EU rules starting 2017-10-29, thus reinstituting winter time. Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously predicted. (Thanks to Dominic Fok.) Adjust future predictions accordingly. Namibia will switch from +01 with DST to +02 all year on 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01 at 02:00. (Thanks to Steffen Thorsen.) Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed Atyya and Yahia Abdalla.) South Sudan is not switching, so Africa/Juba is no longer a link to Africa/Khartoum. Tonga has likely ended its experiment with DST, and will not adjust its clocks on 2017-11-05. Although Tonga has not announced whether it will continue to observe DST, the IATA is assuming that it will not. (Thanks to David Wade.) Turks & Caicos will switch from -04 all year to -05 with US DST on 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04 at 02:00. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
8de8e92017-11-17Henrik Grubbström (Grubba)  Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03. (Thanks to Arthur David Olson.) Detroit did not observe DST in 1967. Use railway time for Asia/Kolkata before 1941, by switching to Madras local time (UT +052110) in 1870, then to IST (UT +0530) in 1906. Also, treat 1941-2's +0630 as DST, like 1942-5. Europe/Dublin's 1946 and 1947 fallback transitions occurred at 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.) Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to American time in 1892, not 1879. (Thanks to Michael Deckers.) Adjust the 1867 transition in Alaska to better reflect the historical record, by changing it to occur on 1867-10-18 at 15:30 Sitka time rather than at the start of 1867-10-17 local time. Although strictly speaking this is accurate only for Sitka, the rest of Alaska's blanks need to be filled in somehow. Fix off-by-one errors in UT offsets for Adak and Nome before 1867. (Thanks to Michael Deckers.) Add 7 s to the UT offset in Asia/Yangon before 1920. Changes to zone names Remove Canada/East-Saskatchewan from the 'backward' file, as it exceeded the 14-character limit and was an unused misnomer anyway. Changes to build procedure To support applications that prefer to read time zone data in text form, two zic input files tzdata.zi and leapseconds are now installed by default. The commands 'zic tzdata.zi' and 'zic -L leapseconds tzdata.zi' can reproduce the tzdata binary files without and with leap seconds, respectively. To prevent these two new files from being installed, use 'make TZDATA_TEXT=', and to suppress leap seconds from the tzdata text installation, use 'make TZDATA_TEXT=tzdata.zi'. 'make BACKWARD=' now suppresses backward-compatibility names like 'US/Pacific' that are defined in the 'backward' and 'pacificnew' files. 'make check' now works on systems that lack a UTF-8 locale, or that lack the nsgmls program. Set UTF8_LOCALE to configure the name of a UTF-8 locale, if you have one. Y2K runtime checks are no longer enabled by default. Add -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU to disable them. (New name suggested by Brian Inglis.) The build procedure for zdump now works on AIX 7.1. (Problem reported by Kees Dekker.) Changes to code zic and the reference runtime now reject multiple leap seconds within 28 days of each other, or leap seconds before the Epoch. As a result, support for double leap seconds, which was obsolescent and undocumented, has been removed. Double leap seconds were an error in the C89 standard; they have never existed in civil timekeeping. (Thanks to Robert Elz and Bradley White for noticing glitches in the code that uncovered this problem.) zic now warns about use of the obsolescent and undocumented -y option, and about use of the obsolescent TYPE field of Rule lines. zic now allows unambiguous abbreviations like "Sa" and "Su" for weekdays; formerly it rejected them due to a bug. Conversely, zic no longer considers non-prefixes to be abbreviations; for example, it no longer accepts "lF" as an abbreviation for "lastFriday". Also, zic warns about the undocumented usage with a "last-" prefix, e.g., "last-Fri". Similarly, zic now accepts the unambiguous abbreviation "L" for "Link" in ordinary context and for "Leap" in leap-second context. Conversely, zic no longer accepts non-prefixes such as "La" as abbreviations for words like "Leap". zic no longer accepts leap second lines in ordinary input, or ordinary lines in leap second input. Formerly, zic sometimes warned about this undocumented usage and handled it incorrectly. The new macro HAVE_TZNAME governs whether the tzname external variable is exported, instead of USG_COMPAT. USG_COMPAT now governs only the external variables "timezone" and "daylight". This change is needed because the three variables are not in the same category: although POSIX requires tzname, it specifies the other two variables as optional. Also, USG_COMPAT is now 1 or 0: if not defined, the code attempts to guess it from other macros. localtime.c and difftime.c no longer require stdio.h, and .c files other than zic.c no longer require sys/wait.h. zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.) Calculation of time_t extrema works around a bug in GCC 4.8.4 (Reported by Stan Shebs and Joseph Myers.) zic.c no longer mistranslates formats of line numbers in non-English locales. (Problem reported by Benno Schulenberg.) Several minor changes have been made to the code to make it a bit easier to port to MS-Windows and Solaris. (Thanks to Kees Dekker for reporting the problems.) Changes to documentation and commentary The two new files 'theory.html' and 'calendars' contain the contents of the removed file 'Theory'. The goal is to document tzdb theory more accessibly. The zic man page now documents abbreviation rules. tz-link.htm now covers how to apply tzdata changes to clients. (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL. The leap-seconds.list URL has been updated to something that is more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
efe4f42017-03-26Henrik Grubbström (Grubba) Release 2017b - 2017-03-17 07:30:38 -0700 Briefly: Haiti has resumed DST.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
efe4f42017-03-26Henrik Grubbström (Grubba)  Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
efe4f42017-03-26Henrik Grubbström (Grubba)  Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01. Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430" is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
8de8e92017-11-17Henrik Grubbström (Grubba)  Changes to code The reference localtime implementation now falls back on the current US daylight-saving transition rules rather than the 1987-2006 rules. This fallback occurs only when (1) the TZ
b401d62018-12-18Henrik Grubbström (Grubba)  environment variable has a value like "AST4ADT" that asks
8de8e92017-11-17Henrik Grubbström (Grubba)  for daylight saving time but does not specify the rules, (2) there is no file by that name, and (3) the TZDEFRULES file cannot be loaded. (Thanks to Tom Lane.)
efe4f42017-03-26Henrik Grubbström (Grubba) 
d8fc842017-03-05Henrik Grubbström (Grubba) Release 2017a - 2017-02-28 00:05:36 -0800 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia discontinues DST.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
d8fc842017-03-05Henrik Grubbström (Grubba)  Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.) Chile's Region of Magallanes moves from -04/-03 to -03 year-round. Its clocks diverge from America/Santiago starting 2017-05-13 at 23:00, hiving off a new zone America/Punta_Arenas. Although the Chilean government says this change expires in May 2019, for now assume it's permanent. (Thanks to Juan Correa and Deborah Goldsmith.) This also affects Antarctica/Palmer.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
d8fc842017-03-05Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  Fix many entries for historical timestamps for Europe/Madrid
d8fc842017-03-05Henrik Grubbström (Grubba)  before 1979, to agree with tables compiled by Pere Planesas of the National Astronomical Observatory of Spain. As a side effect,
b401d62018-12-18Henrik Grubbström (Grubba)  this changes some timestamps for Africa/Ceuta before 1929, which
d8fc842017-03-05Henrik Grubbström (Grubba)  are probably guesswork anyway. (Thanks to Steve Allen and Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for correcting the 1901 transition.) Ecuador observed DST from 1992-11-28 to 1993-02-05. (Thanks to Alois Treindl.) Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21. (Thanks to Stepan Golosunov.) Changes to past and future time zone abbreviations Switch to numeric time zone abbreviations for South America, as part of the ongoing project of removing invented abbreviations. This avoids the need to invent an abbreviation for the new Chilean new zone. Similarly, switch from invented to numeric time zone abbreviations for Afghanistan, American Samoa, the Azores, Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei, Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is, Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland, Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia, the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia, Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau, Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore, Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and Xinjiang; for 20-minute daylight saving time in Ghana before 1943; for half-hour daylight saving time in Belize before 1944 and in the Dominican Republic before 1975; and for Canary Islands before 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for Indian Summer Time before 1942, for Indonesia before around 1964, for Kenya before 1960, for Liberia before 1973, for Madeira before 1967, for Namibia before 1943, for the Netherlands in 1937-9, for Pakistan before 1971, for Western Sahara before 1977, and for Zaporozhye in 1880-1924. For Alaska time from 1900 through 1967, instead of "CAT" use the abbreviation "AST", the abbreviation commonly used at the time (Atlantic Standard Time had not been standardized yet). Use "AWT" and "APT" instead of the invented abbreviations "CAWT" and "CAPT". Use "CST" and "CDT" instead of invented abbreviations for Macau before 1999 and Taiwan before 1938, and use "JST" instead of the invented abbreviation "JCST" for Japan and Korea before 1938. Change to database entry category Move the Pacific/Johnston link from 'australasia' to 'backward', since Johnston is now uninhabited. Changes to code zic no longer mishandles some transitions in January 2038 when it attempts to work around Qt bug 53071. This fixes a bug affecting Pacific/Tongatapu that was introduced in zic 2016e. localtime.c now contains a workaround, useful when loading a file generated by a buggy zic. (Problem and localtime.c fix reported by Bradley White.) zdump -i now outputs non-hour numeric time zone abbreviations without a colon, e.g., "+0530" rather than "+05:30". This agrees with zic %z and with common practice, and simplifies auditing of zdump output. zdump is now buildable again with -DUSE_LTZ=0. (Problem reported by Joseph Myers.) zdump.c now always includes private.h, to avoid code duplication with private.h. (Problem reported by Kees Dekker.) localtime.c no longer mishandles early or late timestamps when TZ is set to a POSIX-style string that specifies DST. (Problem reported by Kees Dekker.) date and strftime now cause %z to generate "-0000" instead of "+0000" when the UT offset is zero and the time zone abbreviation begins with "-". Changes to documentation and commentary The 'Theory' file now better documents choice of historical time zone abbreviations. (Problems reported by Michael Deckers.) tz-link.htm now covers leap smearing, which is popular in clouds.
5bee8d2016-11-26Henrik Grubbström (Grubba) Release 2016j - 2016-11-22 23:17:13 -0800 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
5bee8d2016-11-26Henrik Grubbström (Grubba)  Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00. This hives off a new zone Europe/Saratov from Europe/Volgograd. (Thanks to Yuri Konotopov and Stepan Golosunov.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
5bee8d2016-11-26Henrik Grubbström (Grubba)  The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
d8fc842017-03-05Henrik Grubbström (Grubba)  Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
5bee8d2016-11-26Henrik Grubbström (Grubba)  1999, not fall 1994. (Thanks to Stepan Golosunov.) Changes to past time zone abbreviations Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote summer time before 1948. The old use of "EET" was a typo. Changes to code zic no longer mishandles file systems that lack hard links, fixing bugs introduced in 2016g. (Problems reported by Tom Lane.) Also, when the destination already contains symbolic links, zic should now work better on systems where the 'link' system call does not follow symbolic links. Changes to documentation and commentary tz-link.htm now documents the relationship between release version numbers and development-repository commit tags. (Suggested by Paul Koning.) The 'Theory' file now documents UT. iso3166.tab now accents "Curaçao", and commentary now mentions the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2960e72016-11-04Henrik Grubbström (Grubba) Release 2016i - 2016-11-01 23:19:52 -0700 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga reintroduces DST on 2016-11-06.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
2960e72016-11-04Henrik Grubbström (Grubba)  Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on 2017-01-15 at 03:00. Assume future observances in Tonga will be from the first Sunday in November through the third Sunday in January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric time zone abbreviations for this zone.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
2960e72016-11-04Henrik Grubbström (Grubba)  Northern Cyprus is now +03 year round, causing a split in Cyprus time zones starting 2016-10-30 at 04:00. This creates a zone Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.) Antarctica/Casey switched from +08 to +11 on 2016-10-22. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
2960e72016-11-04Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  Several corrections were made for pre-1975 timestamps in Italy.
2960e72016-11-04Henrik Grubbström (Grubba)  These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and Europe/Vatican. First, the 1893-11-01 00:00 transition in Italy used the new UT offset (+01), not the old (+00:49:56). (Thanks to Michael Deckers.) Second, rules for daylight saving in Italy were changed to agree with Italy's National Institute of Metrological Research (INRiM) except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian Inglis, and Michael Deckers): The 1916-06-03 transition was at 24:00, not 00:00. The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at 00:00, not 01:00. The 1917-09-30 and 1918-10-06 transitions were at 24:00, not 01:00. The 1944-09-17 transition was at 03:00, not 01:00. This particular change is taken from Italian law as INRiM's table, (which says 02:00) appears to have a typo here. Also, keep the 1944-04-03 transition for Europe/Rome, as Rome was controlled by Germany then. The 1967-1970 and 1972-1974 fallback transitions were at 01:00, not 00:00. Changes to code The code should now be buildable on AmigaOS merely by setting the appropriate Makefile variables. (From a patch by Carsten Larsen.)
cca77d2016-10-23Henrik Grubbström (Grubba) Release 2016h - 2016-10-19 23:17:57 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
cca77d2016-10-23Henrik Grubbström (Grubba)  Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that future fall transitions will be on the last Saturday of October at 01:00, which is consistent with predicted spring transitions on the last Saturday of March. (Thanks to Tim Parenti.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
cca77d2016-10-23Henrik Grubbström (Grubba)  In Turkey, transitions in 1986-1990 were at 01:00 standard time not at 02:00, and the spring 1994 transition was on March 20, not March 27. (Thanks to Kıvanç Yazan.) Changes to past and future time zone abbreviations Asia/Colombo now uses numeric time zone abbreviations like "+0530" instead of alphabetic ones like "IST" and "LKT". Various English-language sources use "IST", "LKT" and "SLST", with no working consensus. (Usage of "SLST" mentioned by Sadika Sumanapala.) Changes to code zic no longer mishandles relativizing file names when creating symbolic links like /etc/localtime, when these symbolic links are outside the usual directory hierarchy. This fixes a bug introduced in 2016g. (Problem reported by Andreas Stieger.) Changes to build procedure New rules 'traditional_tarballs' and 'traditional_signatures' for building just the traditional-format distribution. (Requested by Deborah Goldsmith.) The file 'version' is now put into the tzdata tarball too. (Requested by Howard Hinnant.) Changes to documentation and commentary The 'Theory' file now has a section on interface stability. (Requested by Paul Koning.) It also mentions features like tm_zone and localtime_rz that have long been supported by the reference code. tz-link.htm has improved coverage of time zone boundaries suitable for geolocation. (Thanks to heads-ups from Evan Siroky and Matt Johnson.) The US commentary now mentions Allen and the "day of two noons". The Fiji commentary mentions the government's 2016-10-03 press release. (Thanks to Raymond Kumar.) Release 2016g - 2016-09-13 08:56:38 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to future timestamps
cca77d2016-10-23Henrik Grubbström (Grubba)  Turkey switched from EET/EEST (+02/+03) to permanent +03, effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather than an invented abbreviation for the new time. New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52. (Thanks to Tim Parenti.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past timestamps
cca77d2016-10-23Henrik Grubbström (Grubba)  For America/Los_Angeles, spring-forward transition times have been corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in 1950-1966. For zones using Soviet time on 1919-07-01, transitions to UT-based time were at 00:00 UT, not at 02:00 local time. The affected zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.) Changes to past and future time zone abbreviations The Factory zone now uses the time zone abbreviation -00 instead of a long English-language string, as -00 is now the normal way to represent an undefined time zone. Several zones in Antarctica and the former Soviet Union, along with zones intended for ships at sea that cannot use POSIX TZ strings, now use numeric time zone abbreviations instead of invented or obsolete alphanumeric abbreviations. The affected zones are Antarctica/Casey, Antarctica/Davis, Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera, Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok, Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita, Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga, Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin, Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi, Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg, Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11, Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5, Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2, Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8, Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad, Europe/Minsk, Europe/Samara, Europe/Volgograd, and Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM was replaced by +05, whereas MSK and MSD were kept as they are not our invention and are widely used. Changes to zone names Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link. (Thanks to David Massoud.) Changes to code zic no longer generates binary files containing POSIX TZ-like strings that disagree with the local time type after the last explicit transition in the data. This fixes a bug with
b401d62018-12-18Henrik Grubbström (Grubba)  Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps on the reference platform. (Thanks to Alexander Belopolsky for reporting the bug and suggesting a way forward.)
cca77d2016-10-23Henrik Grubbström (Grubba)  If the installed localtime and/or posixrules files are symbolic links, zic now keeps them symbolic links when updating them, for compatibility with platforms like OpenSUSE where other programs configure these files as symlinks. zic now avoids hard linking to symbolic links, avoids some unnecessary mkdir and stat system calls, and uses shorter file names internally. zdump has a new -i option to generate transitions in a more-compact but still human-readable format. This option is experimental, and the output format may change in future versions. (Thanks to Jon Skeet for suggesting that an option was needed, and thanks to Tim Parenti and Chris Rovick for further comments.) Changes to build procedure An experimental distribution format is available, in addition to the traditional format which will continue to be distributed. The new format is a tarball tzdb-VERSION.tar.lz with signature file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory tzdb-VERSION containing the code and data of the traditional two-tarball format, along with extra data that may be useful. (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others for comments about the experimental format.) The release version number is now more accurate in the usual case where releases are built from a Git repository. For example, if 23 commits and some working-file changes have been made since release 2016g, the version number is now something like '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
5bee8d2016-11-26Henrik Grubbström (Grubba)  Tagged releases use the same version number format as before,
cca77d2016-10-23Henrik Grubbström (Grubba)  e.g., '2016g'. To support the more-accurate version number, its specification has moved from a line in the Makefile to a new source file 'version'. The experimental distribution contains a file to2050.tzs that contains what should be the output of 'zdump -i -c 2050' on primary zones. If this file is available, 'make check' now checks that zdump generates this output. 'make check_web' now works on Fedora-like distributions. Changes to documentation and commentary tzfile.5 now documents the new restriction on POSIX TZ-like strings that is now implemented by zic. Comments now cite URLs for some 1917-1921 Russian DST decrees. (Thanks to Alexander Belopolsky.) tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J (thanks to Meno Hochschild) and ThreeTen-Extra, and its description of Java 8 has been brought up to date (thanks to Stephen Colebourne). Its description of local time on Mars has been updated to match current practice, and URLs have been updated and some obsolete ones removed.
bc46d92016-07-09Henrik Grubbström (Grubba) Release 2016f - 2016-07-05 16:26:51 +0200
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
bc46d92016-07-09Henrik Grubbström (Grubba)  The Egyptian government changed its mind on short notice, and Africa/Cairo will not introduce DST starting 2016-07-07 after all. (Thanks to Mina Samuel.) Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00. (Thanks to Stepan Golosunov.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes to past and future timestamps
bc46d92016-07-09Henrik Grubbström (Grubba)  Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone abbreviations instead of invented ones.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
bc46d92016-07-09Henrik Grubbström (Grubba)  Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00. (Thanks to Stepan Golosunov.)
d7462f2016-06-18Henrik Grubbström (Grubba) Release 2016e - 2016-06-14 08:46:16 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
d7462f2016-06-18Henrik Grubbström (Grubba)  Africa/Cairo observes DST in 2016 from July 7 to the end of October. Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.) For future years, guess April's last Thursday to October's last Thursday except for Ramadan.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
d7462f2016-06-18Henrik Grubbström (Grubba)  Locations while uninhabited now use '-00', not 'zzz', as a placeholder time zone abbreviation. This is inspired by Internet RFC 3339 and is more consistent with numeric time zone abbreviations already used elsewhere. The change affects several arctic and antarctic locations, e.g., America/Cambridge_Bay before 1920 and Antarctica/Troll before 2005. Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.) Changes to code zic now outputs a dummy transition at time 2**31 - 1 in zones whose POSIX-style TZ strings contain a '<'. This mostly works around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>. (Thanks to Zhanibek Adilbekov for reporting the Qt bug.) Changes affecting documentation and commentary tz-link.htm says why governments should give plenty of notice for time zone or DST changes, and refers to Matt Johnson's blog post. tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.) Release 2016d - 2016-04-17 22:50:29 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
d7462f2016-06-18Henrik Grubbström (Grubba)  America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30. (Thanks to Alexander Krivenyshev for the heads-up.) Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00. (Thanks to Alexander Krivenyshev and Matt Johnson.) New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29 at 02:00. (Thanks to Stepan Golosunov.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
d7462f2016-06-18Henrik Grubbström (Grubba)  New zone Europe/Kirov, split off from Europe/Volgograd. It covers Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made the same change. (Thanks to Stepan Golosunov.) Russia and nearby locations had daylight-saving transitions on 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan Golosunov.) Many corrections to historical time in Kazakhstan from 1991 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's invented time zone abbreviations with numeric abbreviations. Changes to commentary Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
eb15d12016-04-10Henrik Grubbström (Grubba) Release 2016c - 2016-03-23 00:51:27 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
eb15d12016-04-10Henrik Grubbström (Grubba)  Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.) Chile reverts from permanent to seasonal DST. (Thanks to Juan Correa for the heads-up, and to Tim Parenti for corrections.) Guess that future transitions are August's and May's second Saturdays at 24:00 mainland time. Also, call the period from 2014-09-07 through 2016-05-14 daylight saving time instead of standard time, as that seems more appropriate now.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
eb15d12016-04-10Henrik Grubbström (Grubba)  Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26. (Thanks to Stepan Golosunov.) Changes to commentary Several updates and URLs for historical and proposed Russian changes. (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.) Release 2016b - 2016-03-12 17:30:14 -0800
d7462f2016-06-18Henrik Grubbström (Grubba)  Compatibility note Starting with release 2016b, some data entries cause zic implementations derived from tz releases 2005j through 2015e to issue warnings like "time zone abbreviation differs from POSIX standard (+03)". These warnings should not otherwise affect zic's output and can safely be ignored on today's platforms, as the warnings refer to a restriction in POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the warnings is to upgrade to zic derived from tz releases 2015f and later.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
eb15d12016-04-10Henrik Grubbström (Grubba)  New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on 2016-03-27 at 02:00 local time. They need distinct zones since their post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and Altai Republic, Russia, which will switch from +06 to +07 on the same date and local time. The Astrakhan change is already official; the others have passed the first reading in the State Duma and are extremely likely. Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00. (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson and Stepan Golosunov for followup.) As a trial of a new system that needs less information to be made up, the new zones use numeric time zone abbreviations like "+04" instead of invented abbreviations like "ASTT". Haiti will not observe DST in 2016. (Thanks to Jean Antoine via Steffen Thorsen.) Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00. (Thanks to Hannah Kreitem.) Guess future transitions will be March's last Saturday at 01:00, not March's last Friday at 24:00.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
eb15d12016-04-10Henrik Grubbström (Grubba)  Europe/Chisinau observed DST during 1990, and switched from +04 to +03 at 1990-05-06 02:00, instead of switching from +03 to +02. (Thanks to Stepan Golosunov.) 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not KUYT/KUYST. (Thanks to Stepan Golosunov.) Changes to code tzselect's diagnostics and checking, and checktab.awk's checking, have been improved. (Thanks to J William Piggott.) tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.) tzselect now tests Julian-date TZ settings more accurately. (Thanks to J William Piggott.) Changes to commentary Comments in zone tables have been improved. (Thanks to J William Piggott.) tzselect again limits its menu comments so that menus fit on a
07968a2018-09-05Henrik Grubbström (Grubba)  24×80 alphanumeric display.
eb15d12016-04-10Henrik Grubbström (Grubba)  A new web page tz-how-to.html. (Thanks to Bill Seymour.) In the Theory file, the description of possible time zone abbreviations in tzdata has been cleaned up, as the old description was unclear and inconsistent. (Thanks to Alain Mouette for reporting the problem.)
ac5f542016-02-07Henrik Grubbström (Grubba) Release 2016a - 2016-01-26 23:28:02 -0800
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
ac5f542016-02-07Henrik Grubbström (Grubba)  America/Cayman will not observe daylight saving this year after all. Revert our guess that it would. (Thanks to Matt Johnson.) Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00. (Thanks to Alexander Krivenyshev.) Asia/Tehran now has DST predictions for the year 2038 and later, to be March 21 00:00 to September 21 00:00. This is likely better than predicting no DST, albeit off by a day every now and then.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past and future timestamps
ac5f542016-02-07Henrik Grubbström (Grubba)  America/Metlakatla switched from PST all year to AKST/AKDT on 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.) America/Santa_Isabel has been removed, and replaced with a backward compatibility link to America/Tijuana. Its contents were apparently based on a misreading of Mexican legislation.
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
ac5f542016-02-07Henrik Grubbström (Grubba)  Asia/Karachi's two transition times in 2002 were off by a minute. (Thanks to Matt Johnson.) Changes affecting build procedure An installer can now combine leap seconds with use of the backzone file, e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'. The old 'make posix_packrat' rule is now marked as obsolescent. (Thanks to Ian Abbott for an initial implementation.) Changes affecting documentation and commentary A new file LICENSE makes it easier to see that the code and data are mostly public-domain. (Thanks to James Knight.) The three non-public-domain files now use the current (3-clause) BSD license instead of older versions of that license. tz-link.htm mentions the BDE library (thanks to Andrew Paprocki), CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section on editing tz source files (with a mention of Sublime zoneinfo, thanks to Gilmore Davidson). The Theory and asia files now mention the 2015 book "The Global Transformation of Time, 1870-1950", and cite a couple of reviews. The America/Chicago entry now documents the informal use of US central time in Fort Pierre, South Dakota. (Thanks to Rick McDermid, Matt Johnson, and Steve Jones.)
6cac752015-10-04Henrik Grubbström (Grubba) Release 2015g - 2015-10-01 00:39:51 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
6cac752015-10-04Henrik Grubbström (Grubba)  Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25. (Thanks to Fatih.) Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time. (Thanks to Alexander Krivenyshev.) Fiji's 2016 fall-back transition is scheduled for January 17, not 24. (Thanks to Ken Rylander.) Fort Nelson, British Columbia will not fall back on 2015-11-01. It has effectively been on MST (-0700) since it advanced its clocks on 2015-03-08. New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
6cac752015-10-04Henrik Grubbström (Grubba)  Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00. Changes affecting code localtime no longer mishandles America/Anchorage after 2037. (Thanks to Bradley White for reporting the bug.)
ac5f542016-02-07Henrik Grubbström (Grubba)  On hosts with signed 32-bit time_t, localtime no longer mishandles Pacific/Fiji after 2038-01-16 14:00 UTC.
6cac752015-10-04Henrik Grubbström (Grubba)  The localtime module allows the variables 'timezone', 'daylight', and 'altzone' to be in common storage shared with other modules, and declares them in case the system <time.h> does not. (Problems reported by Kees Dekker.) On platforms with tm_zone, strftime.c now assumes it is not NULL. This simplifies the code and is consistent with zdump.c. (Problem reported by Christos Zoulas.) Changes affecting documentation The tzfile man page now documents that transition times denote the starts (not the ends) of the corresponding time periods. (Ambiguity reported by Bill Seymour.)
7cb6842015-08-15Henrik Grubbström (Grubba) Release 2015f - 2015-08-10 18:06:56 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
7cb6842015-08-15Henrik Grubbström (Grubba)  North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.) The abbreviation remains "KST". (Thanks to Robert Elz.) Uruguay no longer observes DST. (Thanks to Steffen Thorsen and Pablo Camargo.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past and future timestamps
7cb6842015-08-15Henrik Grubbström (Grubba)  Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC. (Thanks to Roman Tudos.) Changes affecting data format and code zic's '-y YEARISTYPE' option is no longer documented. The TYPE field of a Rule line should now be '-'; the old values 'even', 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented. Although the implementation has not changed, these features do not work in the default installation, they are not used in the data, and they are now considered obsolescent. zic now checks that two rules don't take effect at the same time. (Thanks to Jon Skeet and Arthur David Olson.) Constraints on simultaneity are now documented.
07968a2018-09-05Henrik Grubbström (Grubba)  The two characters '%z' in a zone format now stand for the UT offset, e.g., '-07' for seven hours behind UT and '+0530' for
7cb6842015-08-15Henrik Grubbström (Grubba)  five hours and thirty minutes ahead. This better supports time zone abbreviations conforming to POSIX.1-2001 and later. Changes affecting installed data files Comments for America/Halifax and America/Glace_Bay have been improved. (Thanks to Brian Inglis.) Data entries have been simplified for Atlantic/Canary, Europe/Simferopol, Europe/Sofia, and Europe/Tallinn. This yields slightly smaller installed data files for Europe/Simferopol and Europe/Tallinn. It does not affect timestamps. (Thanks to Howard Hinnant.) Changes affecting code zdump and zic no longer warn about valid time zone abbreviations like '-05'. Some Visual Studio 2013 warnings have been suppressed. (Thanks to Kees Dekker.) 'date' no longer sets the time of day and its -a, -d, -n and -t options have been removed. Long obsolescent, the implementation of these features had porting problems. Builders no longer need to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H. (Thanks to Kees Dekker for pointing out the problem.) Changes affecting documentation The Theory file mentions naming issues earlier, as these seem to be poorly publicized (thanks to Gilmore Davidson for reporting the problem). tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant). Mention that Herbert Samuel introduced the term "Summer Time".
638fc82015-08-14Henrik Grubbström (Grubba)  Release 2015e - 2015-06-13 10:56:02 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
638fc82015-08-14Henrik Grubbström (Grubba)  Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00, not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.) Assume Cayman Islands will observe DST starting next year, using US rules. Although it isn't guaranteed, it is the most likely. Changes affecting data format The file 'iso3166.tab' now uses UTF-8, so that its entries can better spell the names of Åland Islands, Côte d'Ivoire, and Réunion. Changes affecting code When displaying data, tzselect converts it to the current locale's encoding if the iconv command works. (Problem reported by random832.) tzselect no longer mishandles Dominica, fixing a bug introduced in Release 2014f. (Problem reported by Owen Leibman.) zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\". This fixes a bug introduced in Release 2014f. (Problem reported by Leonardo Chiquitto.)
c33df72015-05-01Henrik Grubbström (Grubba) Release 2015d - 2015-04-24 08:09:46 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
c33df72015-05-01Henrik Grubbström (Grubba)  Egypt will not observe DST in 2015 and will consider canceling it permanently. For now, assume no DST indefinitely. (Thanks to Ahmed Nazmy and Tim Parenti.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
c33df72015-05-01Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
c33df72015-05-01Henrik Grubbström (Grubba)  1966-07-01. Also, Yukon's time zone history is documented better. (Thanks to Brian Inglis and Dennis Ferguson.) Change affecting past and future time zone abbreviations The abbreviations for Hawaii-Aleutian standard and daylight times have been changed from HAST/HADT to HST/HDT, as per US Government Printing Office style. This affects only America/Adak since 1983, as America/Honolulu was already using the new style. Changes affecting code zic has some minor performance improvements.
db80cc2015-04-16Henrik Grubbström (Grubba) Release 2015c - 2015-04-11 08:55:55 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
db80cc2015-04-16Henrik Grubbström (Grubba)  Egypt's spring-forward transition is at 24:00 on April's last Thursday, not 00:00 on April's last Friday. 2015's transition will therefore be on Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
db80cc2015-04-16Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  The following changes affect some pre-1991 Chile-related timestamps
db80cc2015-04-16Henrik Grubbström (Grubba)  in America/Santiago, Antarctica/Palmer, and Pacific/Easter. The 1910 transition was January 10, not January 1. The 1918 transition was September 10, not September 1.
cca77d2016-10-23Henrik Grubbström (Grubba)  The UT -04 time observed from 1932 to 1942 is now considered to be standard time, not year-round DST.
db80cc2015-04-16Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  Santiago observed DST (UT -03) from 1946-07-15 through 1946-08-31, then reverted to standard time, then switched to -05 on 1947-04-01.
db80cc2015-04-16Henrik Grubbström (Grubba)  Assume transitions before 1968 were at 00:00, since we have no data saying otherwise. The spring 1988 transition was 1988-10-09, not 1988-10-02. The fall 1990 transition was 1990-03-11, not 1990-03-18.
07968a2018-09-05Henrik Grubbström (Grubba)  Assume no UT offset change for Pacific/Easter on 1890-01-01,
db80cc2015-04-16Henrik Grubbström (Grubba)  and omit all transitions on Pacific/Easter from 1942 through 1946 since we have no data suggesting that they existed. One more zone has been turned into a link, as it differed
b401d62018-12-18Henrik Grubbström (Grubba)  from an existing zone only for older timestamps. As usual, this change affects UT offsets in pre-1970 timestamps only.
db80cc2015-04-16Henrik Grubbström (Grubba)  The zone's old contents have been moved to the 'backzone' file. The affected zone is America/Montreal. Changes affecting commentary Mention the TZUpdater tool. Mention "The Time Now". (Thanks to Brandon Ramsey.)
29be4f2015-03-21Henrik Grubbström (Grubba) Release 2015b - 2015-03-19 23:28:11 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
29be4f2015-03-21Henrik Grubbström (Grubba)  Mongolia will start observing DST again this year, from the last Saturday in March at 02:00 to the last Saturday in September at 00:00. (Thanks to Ganbold Tsagaankhuu.) Palestine will start DST on March 28, not March 27. Also, correct the fall 2014 transition from September 26 to October 24. Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
29be4f2015-03-21Henrik Grubbström (Grubba)  The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a regression. (Thanks to Stuart Bishop for reporting the problem.) Some more zones have been turned into links, when they differed
b401d62018-12-18Henrik Grubbström (Grubba)  from existing zones only for older timestamps. As usual, these changes affect UT offsets in pre-1970 timestamps only.
29be4f2015-03-21Henrik Grubbström (Grubba)  Their old contents have been moved to the 'backzone' file. The affected zones are: America/Antigua, America/Cayman, Pacific/Midway, and Pacific/Saipan. Changes affecting time zone abbreviations Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD". (Thanks to Hank W.) Changes affecting code Fix integer overflow bug in reference 'mktime' implementation. (Problem reported by Jörg Richter.) Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries to be used in the same executable as standard-library time_t functions. (Problems reported by Bradley White.) Changes affecting commentary Cite the recent Mexican decree changing Quintana Roo's time zone. (Thanks to Carlos Raúl Perasso.) Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.) Update info about Mars time.
57f5642015-02-14Henrik Grubbström (Grubba) Release 2015a - 2015-01-29 22:35:20 -0800
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
57f5642015-02-14Henrik Grubbström (Grubba)  The Mexican state of Quintana Roo, represented by America/Cancun, will shift from Central Time with DST to Eastern Time without DST on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.) Chile will not change clocks in April or thereafter; its new standard time will be its old daylight saving time. This affects America/Santiago, Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.) New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49. (Thanks to Tim Parenti.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
57f5642015-02-14Henrik Grubbström (Grubba)  Iceland observed DST in 1919 and 1921, and its 1939 fallback transition was Oct. 29, not Nov. 29. Remove incorrect data from Shanks about time in Iceland between 1837 and 1908. Some more zones have been turned into links, when they differed
b401d62018-12-18Henrik Grubbström (Grubba)  from existing zones only for older timestamps. As usual, these changes affect UT offsets in pre-1970 timestamps only.
57f5642015-02-14Henrik Grubbström (Grubba)  Their old contents have been moved to the 'backzone' file. The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait, and Asia/Muscat. Changes affecting code tzalloc now scrubs time zone abbreviations compatibly with the way that tzset always has, by replacing invalid bytes with '_' and by shortening too-long abbreviations. tzselect ports to POSIX awk implementations, no longer mishandles POSIX TZ settings when GNU awk is used, and reports POSIX TZ settings to the user. (Thanks to Stefan Kuhn.) Changes affecting build procedure 'make check' now checks for links to links in the data. One such link (for Africa/Asmera) has been fixed. (Thanks to Stephen Colebourne for pointing out the problem.) Changes affecting commentary The leapseconds file commentary now mentions the expiration date. (Problem reported by Martin Burnicki.) Update Mexican Library of Congress URL.
792c682014-11-13Henrik Grubbström (Grubba) Release 2014j - 2014-11-10 17:37:11 -0800
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting current and future timestamps
792c682014-11-13Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  Turks & Caicos' switch from US eastern time to UT -04 year-round
792c682014-11-13Henrik Grubbström (Grubba)  did not occur on 2014-11-02 at 02:00. It's currently scheduled for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
792c682014-11-13Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  Many pre-1989 timestamps have been corrected for Asia/Seoul and
792c682014-11-13Henrik Grubbström (Grubba)  Asia/Pyongyang, based on sources for the Korean-language Wikipedia entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no longer guess that Pyongyang mimicked Seoul time after World War II, as this is politically implausible. Some more zones have been turned into links, when they differed
b401d62018-12-18Henrik Grubbström (Grubba)  from existing zones only for older timestamps. As usual, these changes affect UT offsets in pre-1970 timestamps only.
792c682014-11-13Henrik Grubbström (Grubba)  Their old contents have been moved to the 'backzone' file. The affected zones are: Africa/Addis_Ababa, Africa/Asmara, Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala, Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and Indian/Mayotte. Changes affecting commentary The commentary is less enthusiastic about Shanks as a source, and is more careful to distinguish UT from UTC.
6f2cda2014-10-24Henrik Grubbström (Grubba) Release 2014i - 2014-10-21 22:04:57 -0700
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting future timestamps
6f2cda2014-10-24Henrik Grubbström (Grubba)  Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00. (Thanks to Ken Rylander for the heads-up.) Guess that future years will use a similar pattern. A new Zone Pacific/Bougainville, for the part of Papua New Guinea
cca77d2016-10-23Henrik Grubbström (Grubba)  that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
6f2cda2014-10-24Henrik Grubbström (Grubba)  (Thanks to Kiley Walbom for the heads-up.) Changes affecting time zone abbreviations Since Belarus is not changing its clocks even though Moscow is, the time zone abbreviation in Europe/Minsk is changing from FET to its more-traditional value MSK on 2014-10-26 at 01:00. (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
cca77d2016-10-23Henrik Grubbström (Grubba)  The new abbreviation IDT stands for the pre-1976 use of UT +08 in Indochina, to distinguish it better from ICT (+07).
6f2cda2014-10-24Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  Changes affecting past timestamps
6f2cda2014-10-24Henrik Grubbström (Grubba) 
b401d62018-12-18Henrik Grubbström (Grubba)  Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
6f2cda2014-10-24Henrik Grubbström (Grubba)  (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's authoritative book). Asia/Ho_Chi_Minh has been added to zone1970.tab, to give tzselect users in Vietnam two choices, since north and south Vietnam disagreed after our 1970 cutoff. Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
b401d62018-12-18Henrik Grubbström (Grubba)  they differed from existing zones only for older timestamps. As usual, these changes affect pre-1970 timestamps only. Their old
6f2cda2014-10-24Henrik Grubbström (Grubba)  contents have been moved to the 'backzone' file. Changes affecting code The time-related library functions now set errno on failure, and some crashes in the new tzalloc-related library functions have been fixed. (Thanks to Christos Zoulas for reporting most of these problems and for suggesting fixes.)
d8fc842017-03-05Henrik Grubbström (Grubba)  If USG_COMPAT is defined and the requested timestamp is standard time,
6f2cda2014-10-24Henrik Grubbström (Grubba)  the tz library's localtime and mktime functions now set the extern
d8fc842017-03-05Henrik Grubbström (Grubba)  variable timezone to a value appropriate for that timestamp; and
6f2cda2014-10-24Henrik Grubbström (Grubba)  similarly for ALTZONE, daylight saving time, and the altzone variable. This change is a companion to the tzname change in 2014h, and is designed to make timezone and altzone more compatible with tzname. The tz library's functions now set errno to EOVERFLOW if they fail because the result cannot be represented. ctime and ctime_r now
d8fc842017-03-05Henrik Grubbström (Grubba)  return NULL and set errno when a timestamp is out of range, rather
6f2cda2014-10-24Henrik Grubbström (Grubba)  than having undefined behavior. Some bugs associated with the new 2014g functions have been fixed. This includes a bug that largely incapacitated the new functions time2posix_z and posix2time_z. (Thanks to Christos Zoulas.) It also includes some uses of uninitialized variables after tzalloc. The new code uses the standard type 'ssize_t', which the Makefile now gives porting advice about. Changes affecting commentary Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
a6d1842014-10-16Henrik Grubbström (Grubba) Release 2014h - 2014-09-25 18:59:03 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps
a6d1842014-10-16Henrik Grubbström (Grubba)  America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28. Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01, not 1920-01-06. The old entry was based on a misinterpretation of Shanks. Some more zones have been turned into links, when they differed
d8fc842017-03-05Henrik Grubbström (Grubba)  from existing zones only for older timestamps. As usual,
07968a2018-09-05Henrik Grubbström (Grubba)  these changes affect UT offsets in pre-1970 timestamps only.
a6d1842014-10-16Henrik Grubbström (Grubba)  Their old contents have been moved to the 'backzone' file. The affected zones are: Africa/Blantyre, Africa/Bujumbura, Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi, Africa/Lusaka, Africa/Maseru, and Africa/Mbabane. Changes affecting code zdump -V and -v now output gmtoff= values on all platforms, not merely on platforms defining TM_GMTOFF. The tz library's localtime and mktime functions now set tzname to a value
d8fc842017-03-05Henrik Grubbström (Grubba)  appropriate for the requested timestamp, and zdump now uses this
a6d1842014-10-16Henrik Grubbström (Grubba)  on platforms not defining TM_ZONE, fixing a 2014g regression. (Thanks to Tim Parenti for reporting the problem.) The tz library no longer sets tzname if localtime or mktime fails. zdump -c no longer mishandles transitions near year boundaries. (Thanks to Tim Parenti for reporting the problem.)
cca77d2016-10-23Henrik Grubbström (Grubba)  An access to uninitialized data has been fixed.
a6d1842014-10-16Henrik Grubbström (Grubba)  (Thanks to Jörg Richter for reporting the problem.) When THREAD_SAFE is defined, the code ports to the C11 memory model. A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined and two threads race to initialize data used by gmtime-like functions. (Thanks to Andy Heninger for reporting the problems.) Changes affecting build procedure 'make check' now checks better for properly-sorted data. Changes affecting documentation and commentary zdump's gmtoff=N output is now documented, and its isdst=D output is now documented to possibly output D values other than 0 or 1. zdump -c's treatment of years is now documented to use the Gregorian calendar and Universal Time without leap seconds, and its behavior at cutoff boundaries is now documented better. (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.) Programs are now documented to use the proleptic Gregorian calendar. (Thanks to Alan Barrett for the suggestion.) Fractional-second GMT offsets have been documented for civil time in 19th-century Chennai, Jakarta, and New York.
1e27ed2014-09-04Henrik Grubbström (Grubba) Release 2014g - 2014-08-28 12:31:23 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  Turks & Caicos is switching from US eastern time to UT -04 year-round, modeled as a switch on 2014-11-02 at 02:00.
792c682014-11-13Henrik Grubbström (Grubba)  [As noted in 2014j, this switch was later delayed.]
1e27ed2014-09-04Henrik Grubbström (Grubba) 
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Time in Russia or the USSR before 1926 or so has been corrected by a few seconds in the following zones: Asia/Irkutsk, Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi, Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For Asia/Yekaterinburg the correction is a few minutes. (Thanks to Vladimir Karpinsky.) The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
d8fc842017-03-05Henrik Grubbström (Grubba)  This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
1e27ed2014-09-04Henrik Grubbström (Grubba)  Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32. (Thanks to Stephen Colebourne for pointing to the decree.) Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59. A new file 'backzone' contains data which may appeal to
d8fc842017-03-05Henrik Grubbström (Grubba)  connoisseurs of old timestamps, although it is out of scope for
1e27ed2014-09-04Henrik Grubbström (Grubba)  the tz database, is often poorly sourced, and contains some data that is known to be incorrect. The new file is not recommended for ordinary use and its entries are not installed by default. (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and Isle of Man entries.) Some more zones have been turned into links, when they differed
d8fc842017-03-05Henrik Grubbström (Grubba)  from existing zones only for older timestamps. As usual,
07968a2018-09-05Henrik Grubbström (Grubba)  these changes affect UT offsets in pre-1970 timestamps only.
1e27ed2014-09-04Henrik Grubbström (Grubba)  Their old contents have been moved to the 'backzone' file. The affected zones are: Africa/Bangui, Africa/Brazzaville, Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda, Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo. Changes affecting code Unless NETBSD_INSPIRED is defined to 0, the tz library now supplies functions for creating and using objects that represent
b401d62018-12-18Henrik Grubbström (Grubba)  timezones. The new functions are tzalloc, tzfree, localtime_rz,
1e27ed2014-09-04Henrik Grubbström (Grubba)  mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and time2posix_z. They are intended for performance: for example, localtime_rz (unlike localtime_r) is trivially thread-safe without locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired functions, and to Alan Barrett and Jonathan Lennox for helping to debug the change.) zdump now builds with the tz library unless USE_LTZ is defined to 0, This lets zdump use tz features even if the system library lacks them. To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='. zdump now uses localtime_rz if available, as it's significantly faster,
b401d62018-12-18Henrik Grubbström (Grubba)  and it can help zdump better diagnose invalid timezone names.
1e27ed2014-09-04Henrik Grubbström (Grubba)  Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is not available, zdump now uses localtime_r and tzset if available, as this is a bit cleaner and faster than plain localtime. Compile with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system lacks these two functions. If THREAD_SAFE is defined to 1, the tz library is now thread-safe. Although not needed for tz's own applications, which are single-threaded, this supports POSIX better if the tz library is used in multithreaded apps. Some crashes have been fixed when zdump or the tz library is given invalid or outlandish input. The tz library no longer mishandles leap seconds on platforms with
b401d62018-12-18Henrik Grubbström (Grubba)  unsigned time_t in timezones that lack ordinary transitions after 1970.
1e27ed2014-09-04Henrik Grubbström (Grubba)  The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not already defined, to make it easier to configure on common platforms. Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this. Unless the new macro UNINIT_TRAP is defined to 1, the tz code now assumes that reading uninitialized memory yields garbage values but does not cause other problems such as traps. If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
d8fc842017-03-05Henrik Grubbström (Grubba)  more likely to guess right for ambiguous timestamps near
1e27ed2014-09-04Henrik Grubbström (Grubba)  transitions where tm_isdst does not change. If HAVE_STRFTIME_L is defined to 1, the tz library now defines strftime_l for compatibility with recent versions of POSIX. Only the C locale is supported, though. HAVE_STRFTIME_L defaults to 1 on recent POSIX versions, and to 0 otherwise. tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used, or when time_tz is defined. When HAVE_UTMPX_H is set the 'date' command now builds on systems whose <utmpx.h> file does not define WTMPX_FILE, and when setting the date it updates the wtmpx file if _PATH_WTMPX is defined. This affects GNU/Linux and similar systems. For easier maintenance later, some C code has been simplified, some lint has been removed, and the code has been tweaked so that plain 'make' is more likely to work. The C type 'bool' is now used for boolean values, instead of 'int'. The long-obsolete LOCALE_HOME code has been removed. The long-obsolete 'gtime' function has been removed. Changes affecting build procedure 'zdump' no longer links in ialloc.o, as it's not needed. 'make check_time_t_alternatives' no longer assumes GNU diff. Changes affecting distribution tarballs The files checktab.awk and zoneinfo2tdf.pl are now distributed in the tzdata tarball instead of the tzcode tarball, since they help maintain the data. The NEWS and Theory files are now also distributed in the tzdata tarball, as they're relevant for data. (Thanks to Alan Barrett for pointing this out.) Also, the leapseconds.awk file is no longer distributed in the tzcode tarball, since it belongs in the tzdata tarball (where 2014f inadvertently also distributed it). Changes affecting documentation and commentary A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms for debugging it.) The man pages have been updated to use function prototypes, to document thread-safe variants like localtime_r, and to document the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and mktime_z. The fields in Link lines have been renamed to be more descriptive and more like the parameters of 'ln'. LINK-FROM has become TARGET, and LINK-TO has become LINK-NAME. tz-link.htm mentions the IETF's tzdist working group; Windows Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab. Some broken URLs have been fixed in the commentary. (Thanks to Lester Caine.) Commentary about Philippines DST has been updated, and commentary on pre-1970 time in India has been added. Release 2014f - 2014-08-05 17:42:36 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Russia will subtract an hour from most of its time zones on 2014-10-26 at 02:00 local time. (Thanks to Alexander Krivenyshev.) There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic (Europe/Samara) are not changing their clocks. The changed zones are Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd, Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk, Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga, Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected, but not its UTC offset. Two zones are added: Asia/Chita (split from Asia/Yakutsk, and also with two hours subtracted) and Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour subtracted). (Thanks to Tim Parenti for much of the above.) Changes affecting time zone abbreviations Australian eastern time zone abbreviations are now AEST/AEDT not EST, and similarly for the other Australian zones. That is, for eastern standard and daylight saving time the abbreviations are AEST and AEDT instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT, and AWST/AWDT are now used instead of the former CST, CWST, and WST.
07968a2018-09-05Henrik Grubbström (Grubba)  This change does not affect UT offsets, only time zone abbreviations.
1e27ed2014-09-04Henrik Grubbström (Grubba)  (Thanks to Rich Tibbett and many others.)
cca77d2016-10-23Henrik Grubbström (Grubba)  Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
1e27ed2014-09-04Henrik Grubbström (Grubba)  effective 2014-10-26 at 02:00 local time. The time zone abbreviation for Xinjiang Time (observed in Ürümqi) has been changed from URUT to XJT. (Thanks to Luther Ma.) Prefer MSK/MSD for Moscow time in Russia, even in other cities. Similarly, prefer EET/EEST for eastern European time in Russia. Change time zone abbreviations in (western) Samoa to use "ST" and "DT" suffixes, as this is more likely to match common practice. Prefix "W" to (western) Samoa time when its standard-time offset disagrees with that of American Samoa. America/Metlakatla now uses PST, not MeST, to abbreviate its time zone. Time zone abbreviations have been updated for Japan's two time zones used 1896-1937. JWST now stands for Western Standard Time, and JCST for Central Standard Time (formerly this was CJT). These abbreviations are now used for time in Korea, Taiwan, and Sakhalin while controlled by Japan.
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  China's five zones have been simplified to two, since the post-1970 differences in the other three seem to have been imaginary. The zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been removed; backwards-compatibility links still work, albeit with
d8fc842017-03-05Henrik Grubbström (Grubba)  different behaviors for timestamps before May 1980. Asia/Urumqi's
cca77d2016-10-23Henrik Grubbström (Grubba)  1980 transition to UT +08 has been removed, so that it is now at +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
1e27ed2014-09-04Henrik Grubbström (Grubba)  Treindl sent helpful translations of two papers by Guo Qingsheng.) Some zones have been turned into links, when they differed from existing
07968a2018-09-05Henrik Grubbström (Grubba)  zones only for older UT offsets where data entries were likely invented. These changes affect UT offsets in pre-1970 timestamps only. This is
1e27ed2014-09-04Henrik Grubbström (Grubba)  similar to the change in release 2013e, except this time for western Africa. The affected zones are: Africa/Bamako, Africa/Banjul, Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome, Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and Atlantic/St_Helena. This also affects the backwards-compatibility link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne, Tim Parenti, and David Patte for reporting problems in earlier versions of this change.) Asia/Shanghai's pre-standard-time UT offset has been changed from 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its transition to standard time has been changed from 1928 to 1901. Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01, then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945. In 1946 it observed DST from 05-15 through 09-30; in 1947 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30. (Thanks to Yu-Cheng Chuang.) Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950. Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
cca77d2016-10-23Henrik Grubbström (Grubba)  Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the period from 1911 to 1950.
1e27ed2014-09-04Henrik Grubbström (Grubba)  Pacific/Chatham has been changed to New Zealand standard time plus 45 minutes for the period before 1957, reflecting a 1956 remark in the New Zealand parliament. Europe/Budapest has several pre-1946 corrections: in 1918 the transition out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08 not 04-06 at 02:00; and there was no DST in 1920. Africa/Accra is now assumed to have observed DST from 1920 through 1935. Time in Russia before 1927 or so has been corrected by a few seconds in the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi, Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0 point. (Thanks to Vladimir Karpinsky for the Moscow changes.) Changes affecting data format A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data. The new file's extended format allows multiple country codes per zone. The older file is still installed but is deprecated; its format is not changing and it will still be distributed for a while, but new applications should use the new file. The new file format simplifies maintenance of obscure locations. To test this, it adds coverage for the Crozet Islands and the Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.) The file 'iso3166.tab' is planned to switch from ASCII to UTF-8. It is still ASCII now, but commentary about the switch has been added. The new file 'zone1970.tab' already uses UTF-8. Changes affecting code 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE is defined. (Thanks to Elliott Hughes for reporting the problem.) 'zic' no longer mishandles input when ignoring case in locales that are not compatible with English, e.g., unibyte Turkish locales when compiled with HAVE_GETTEXT. Error diagnostics of 'zic' and 'yearistype' have been reworded so that they no longer use ASCII '-' as if it were a dash. 'zic' now rejects output file names that contain '.' or '..' components. (Thanks to Tim Parenti for reporting the problem.) 'zic -v' now warns about output file names that do not follow POSIX rules, or that contain a digit or '.'. (Thanks to Arthur David Olson for starting the ball rolling on this.) Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0. Changes affecting build procedure 'zic' no longer links in localtime.o and asctime.o, as they're not needed. (Thanks to John Cochran.) Changes affecting documentation and commentary The 'Theory' file documents legacy names, the longstanding exceptions to the POSIX-inspired file name rules. The 'zic' documentation clarifies the role of time types when interpreting dates. (Thanks to Arthur David Olson.) Documentation and commentary now prefer UTF-8 to US-ASCII, allowing the use of proper accents in foreign words and names. Code and data have not changed because of this. (Thanks to Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug this.) Non-HTML documentation and commentary now use plain-text URLs instead of HTML insertions, and are more consistent about bracketing URLs when they are not already surrounded by white space. (Thanks to suggestions by Steffen Nurpmeso.) There is new commentary about Xujiahui Observatory, the five time-zone project in China from 1918 to 1949, timekeeping in Japanese-occupied Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the warlord Jin Shuren in the data. Commentary about the coverage of each Russian zone has been standardized. (Thanks to Tim Parenti). There is new commentary about contemporary timekeeping in Ethiopia. Obsolete comments about a 2007 proposal for DST in Kuwait has been removed. There is new commentary about time in Poland in 1919. Proper credit has been given to DST inventor George Vernon Hudson. Commentary about time in Metlakatla, AK and Resolute, NU has been improved, with a new source for the former. In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it is uninhabited. Commentary about permanent Antarctic bases has been updated. Several typos have been corrected. (Thanks to Tim Parenti for contributing some of these fixes.) tz-link.htm now mentions the JavaScript libraries Moment Timezone, TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up from Matt Johnson.) Also, it mentions the Go 'latlong' package. (Thanks to a heads-up from Dirkjan Ochtman.) The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998 have been removed. These obsolescent US Naval Observatory entries were no longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.) Release 2014e - 2014-06-12 21:53:52 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00. (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily switch to standard time at 24:00 the last Thursday before Ramadan, and back to DST at 00:00 the first Friday after Ramadan. Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks to Milamber Space Network.) Guess that from 2015 on Morocco will temporarily switch to standard time at 03:00 the last Saturday before Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of "MSD" for Moscow's double daylight time in summer 1921. Also, a typo "VLASST" has been repaired to be "VLAST" for Vladivostok summer time in 1991. (Thanks to Hank W. for reporting the problems.) Changes affecting commentary tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and removes stale pointers to World Time Explorer and WORLDTIME. Release 2014d - 2014-05-27 21:34:40 -0700 Changes affecting code
d8fc842017-03-05Henrik Grubbström (Grubba)  zic no longer generates files containing timestamps before the Big Bang.
b401d62018-12-18Henrik Grubbström (Grubba)  This works around GNOME glib bug 878 <https://gitlab.gnome.org/GNOME/glib/issues/878>
1e27ed2014-09-04Henrik Grubbström (Grubba)  (Thanks to Leonardo Chiquitto for reporting the bug, and to Arthur David Olson and James Cloos for suggesting improvements to the fix.) Changes affecting documentation tz-link.htm now mentions GNOME. Release 2014c - 2014-05-13 07:44:13 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Egypt observes DST starting 2014-05-15 at 24:00. (Thanks to Ahmad El-Dardiry and Gunther Vermier.) Details have not been announced, except that DST will not be observed during Ramadan. Guess that DST will stop during the same Ramadan dates as Morocco, and that Egypt's future spring and fall transitions will be the same as 2010 when it last observed DST, namely April's last Friday at 00:00 to September's last Thursday at 23:00 standard time. Also, guess that Ramadan transitions will be at 00:00 standard time. Changes affecting code zic now generates transitions for minimum time values, eliminating guesswork
d8fc842017-03-05Henrik Grubbström (Grubba)  when handling low-valued timestamps. (Thanks to Arthur David Olson.)
1e27ed2014-09-04Henrik Grubbström (Grubba)  Port to Cygwin sans glibc. (Thanks to Arthur David Olson.) Changes affecting commentary and documentation Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.) Release 2014b - 2014-03-24 21:28:50 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Crimea switches to Moscow time on 2014-03-30 at 02:00 local time. (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU. New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and Bengt-Inge Larsson.) This is currently an approximation; a better version will require the zic and localtime fixes mentioned below, and the plan is to wait for a while until at least the zic fixes propagate. Changes affecting code 'zic' and 'localtime' no longer reject locations needing four transitions per year for the foreseeable future. (Thanks to Andrew Main (Zefram).) Also, 'zic' avoids some unlikely failures due to integer overflow. Changes affecting build procedure 'make check' now detects Rule lines defined but never used. The NZAQ rules, an instance of this problem, have been removed. Changes affecting commentary and documentation Fix Tuesday/Thursday typo in description of time in Israel. (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.) Microsoft Windows 8.1 doesn't support tz database names. (Thanks to Donald MacQueen.) Instead, the Microsoft Windows Store app library supports them. Add comments about Johnston Island time in the 1960s. (Thanks to Lyle McElhaney.) Morocco's 2014 DST start will be as predicted. (Thanks to Sebastien Willemijns.) Release 2014a - 2014-03-07 23:30:29 -0800
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for the heads-up, and to Tim Parenti for simplifying the update.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00. (Thanks to Steffen Thorsen.) Ukraine switched from Moscow to Eastern European time on 1990-07-01 (not 1992-01-01), and observed DST during the entire next winter. (Thanks to Vladimir in Moscow via Alois Treindl.) In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03. (Thanks to Avigdor Finkelstein.) Changes affecting code A uninitialized-storage bug in 'localtime' has been fixed. (Thanks to Logan Chien.) Changes affecting the build procedure The settings for 'make check_web' now default to Ubuntu 13.10. Changes affecting commentary and documentation The boundary of the US Pacific time zone is given more accurately. (Thanks to Alan Mintz.) Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.) Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.) Better descriptions of countries with same time zone history as Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.) Several changes affect tz-link.htm, the main web page. Mention Time.is (thanks to Even Scharning) and WX-now (thanks to David Braverman). Mention xCal (Internet RFC 6321) and jCal. Microsoft has some support for tz database names. CLDR data formats include both XML and JSON. Mention Maggiolo's map of solar vs standard time. (Thanks to Arthur David Olson.) Mention TZ4Net. (Thanks to Matt Johnson.) Mention the timezone-olson Haskell package. Mention zeitverschiebung.net. (Thanks to Martin Jäger.) Remove moribund links to daylight-savings-time.info and to Simple Timer + Clocks. Update two links. (Thanks to Oscar van Vlijmen.) Fix some formatting glitches, e.g., remove random newlines from abbr elements' title attributes. Release 2013i - 2013-12-17 07:25:23 -0800
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Jordan switches back to standard time at 00:00 on December 20, 2013. The 2006-2011 transition schedule is planned to resume in 2014. (Thanks to Steffen Thorsen.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  In 2004, Cuba began DST on March 28, not April 4. (Thanks to Steffen Thorsen.) Changes affecting code The compile-time flag NOSOLAR has been removed, as nowadays the benefit of slightly shrinking runtime table size is outweighed by the cost of disallowing potential future updates that exceed old limits. Changes affecting documentation and commentary The files solar87, solar88, and solar89 are no longer distributed. They were a negative experiment - that is, a demonstration that tz data can represent solar time only with some difficulty and error. Their presence in the distribution caused confusion, as Riyadh civil time was generally not solar time in those years. tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.) Release 2013h - 2013-10-25 15:32:32 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting current and future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  Libya has switched its UT offset back to +02 without DST, instead of +01 with DST. (Thanks to Even Scharning.)
1e27ed2014-09-04Henrik Grubbström (Grubba)  Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules. (Thanks to Gwillim Law.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba) 
cca77d2016-10-23Henrik Grubbström (Grubba)  Acre and (we guess) western Amazonas will switch from UT -04 to -05
1e27ed2014-09-04Henrik Grubbström (Grubba)  on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe. (Thanks to Steffen Thorsen.) Add entries for DST transitions in Morocco in the year 2038. This avoids some year-2038 glitches introduced in 2013g. (Thanks to Yoshito Umaoka for reporting the problem.) Changes affecting API The 'tzselect' command no longer requires the 'select' command, and should now work with /bin/sh on more platforms. It also works around a bug in BusyBox awk before version 1.21.0. (Thanks to Patrick 'P. J.' McDermott and Alan Barrett.) Changes affecting code Fix localtime overflow bugs with 32-bit unsigned time_t. zdump no longer assumes sscanf returns maximal values on overflow. Changes affecting the build procedure The builder can specify which programs to use, if any, instead of 'ar' and 'ranlib', and libtz.a is now built locally before being installed. (Thanks to Michael Forney.) A dependency typo in the 'zdump' rule has been fixed. (Thanks to Andrew Paprocki.) The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f' work as specified by POSIX.2-1992 or later; this is portable nowadays. 'make clean' no longer removes 'leapseconds', since it's host-independent and is part of the distribution. The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed. Changes affecting documentation and commentary tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle). Update URLs in tz-link page. Add URLs for Microsoft Windows, since 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no longer maintained) and for old advisories. SOFA now does C. Release 2013g - 2013-09-30 21:08:26 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting current and near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Morocco now observes DST from the last Sunday in March to the last Sunday in October, not April to September respectively. (Thanks to Steffen Thorsen.) Changes affecting 'zic' 'zic' now runs on platforms that lack both hard links and symlinks. (Thanks to Theo Veenker for reporting the problem, for MinGW.) Also, fix some bugs on platforms that lack hard links but have symlinks. 'zic -v' again warns that Asia/Tehran has no POSIX environment variable to predict the far future, fixing a bug introduced in 2013e. Changes affecting the build procedure The 'leapseconds' file is again put into the tzdata tarball. Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to Matt Burgess and Ian Abbott.) The timestamps of these and other dependent files in tarballs are adjusted more consistently. Changes affecting documentation and commentary The README file is now part of the data tarball as well as the code. It now states that files are public domain unless otherwise specified. (Thanks to Andrew Main (Zefram) for asking for clarifications.) Its details about the 1989 release moved to a place of honor near the end of NEWS. Release 2013f - 2013-09-24 23:37:36 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  Tocantins will very likely not observe DST starting this spring. (Thanks to Steffen Thorsen.)
cca77d2016-10-23Henrik Grubbström (Grubba)  Jordan will likely stay at UT +03 indefinitely, and will not fall
1e27ed2014-09-04Henrik Grubbström (Grubba)  back this fall. Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.) Changes affecting API The types of the global variables 'timezone' and 'altzone' (if present) have been changed back to 'long'. This is required for 'timezone' by POSIX, and for 'altzone' by common practice, e.g., Solaris 11. These variables were originally 'long' in the tz code, but were mistakenly changed to 'time_t' in 1987; nobody reported the incompatibility until now. The difference matters on x32, where 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.) Changes affecting the build procedure Avoid long strings in leapseconds.awk to work around a mawk bug. (Thanks to Cyril Baurand.) Changes affecting documentation and commentary New file 'NEWS' that contains release notes like this one. Paraguay's law does not specify DST transition time; 00:00 is customary. (Thanks to Waldemar Villamayor-Venialbo.) Minor capitalization fixes. Changes affecting version-control only The experimental GitHub repository now contains annotated and signed tags for recent releases, e.g., '2013e' for Release 2013e. Releases are tagged starting with 2012e; earlier releases were done differently, and tags would either not have a simple name or not exactly match what was released. 'make set-timestamps' is now simpler and a bit more portable. Release 2013e - 2013-09-19 23:50:04 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting near-future timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  This year Fiji will start DST on October 27, not October 20. (Thanks to David Wheeler for the heads-up.) For now, guess that Fiji will continue to spring forward the Sunday before the fourth Monday in October. Changes affecting current and future time zone abbreviations Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian time zone abbreviations since 1932. (Thanks to George Ziegler, Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura, Asia/Makassar, and Asia/Pontianak.
cca77d2016-10-23Henrik Grubbström (Grubba)  Use ART (UT -03, standard time), rather than WARST (also -03, but
1e27ed2014-09-04Henrik Grubbström (Grubba)  daylight saving time) for San Luis, Argentina since 2009.
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting Godthåb timestamps after 2037 if version mismatch
1e27ed2014-09-04Henrik Grubbström (Grubba)  Allow POSIX-like TZ strings where the transition time's hour can range from -167 through 167, instead of the POSIX-required 0 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the new Fiji rules. This is a more-compact way to represent
d8fc842017-03-05Henrik Grubbström (Grubba)  far-future timestamps for America/Godthab, America/Santiago,
1e27ed2014-09-04Henrik Grubbström (Grubba)  Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem, Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by this change. (Derived from a suggestion by Arthur David Olson.) Allow POSIX-like TZ strings where daylight saving time is in effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western Argentina Summer Time all year. This supports a more-compact way to represent the 2013d data for America/Argentina/San_Luis. Because of the change for San Luis noted above this change does not affect the current data. (Thanks to Andrew Main (Zefram) for suggestions that improved this change.) Where these two TZ changes take effect, there is a minor extension to the tz file format in that it allows new values for the embedded TZ-format string, and the tz file format version number has therefore been increased from 2 to 3 as a precaution. Version-2-based client code should continue to work as before for
d8fc842017-03-05Henrik Grubbström (Grubba)  all timestamps before 2038. Existing version-2-based client code
1e27ed2014-09-04Henrik Grubbström (Grubba)  (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
d8fc842017-03-05Henrik Grubbström (Grubba)  files, and typically works in practice even for timestamps after
1e27ed2014-09-04Henrik Grubbström (Grubba)  2037; the only known exception is America/Godthab.
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting timestamps before 1970
1e27ed2014-09-04Henrik Grubbström (Grubba)  Pacific/Johnston is now a link to Pacific/Honolulu. This corrects some errors before 1947. Some zones have been turned into links, when they differ from existing zones only in older data entries that were likely invented or that differ only in LMT or transitions from LMT. These changes affect
d8fc842017-03-05Henrik Grubbström (Grubba)  only timestamps before 1943. The affected zones are:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Africa/Juba, America/Anguilla, America/Aruba, America/Dominica, America/Grenada, America/Guadeloupe, America/Marigot, America/Montserrat, America/St_Barthelemy, America/St_Kitts, America/St_Lucia, America/St_Thomas, America/St_Vincent, America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for confirming that the old Europe/Vaduz zone was wrong and the new link is better for WWII-era times.) Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
d8fc842017-03-05Henrik Grubbström (Grubba)  America/Cayman, America/Jamaica and America/Grand_Turk timestamps
1e27ed2014-09-04Henrik Grubbström (Grubba)  from 1890 to 1912. Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
d8fc842017-03-05Henrik Grubbström (Grubba)  This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
1e27ed2014-09-04Henrik Grubbström (Grubba)  to Alois Treindl). Change the date of the circa-1850 Zurich transition from 1849-09-12 to 1853-07-16, overriding Shanks with data from Messerli about postal and telegraph time in Switzerland. Changes affecting time zone abbreviations before 1970 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932, as Jakarta was called Batavia back then. Changes affecting API The 'zic' command now outputs a dummy transition when far-future data can't be summarized using a TZ string, and uses a 402-year window rather than a 400-year window. For the current data, this affects only the Asia/Tehran file. It does not affect any of the
d8fc842017-03-05Henrik Grubbström (Grubba)  timestamps that this file represents, so zdump outputs the same
1e27ed2014-09-04Henrik Grubbström (Grubba)  information as before. (Thanks to Andrew Main (Zefram).) The 'date' command has a new '-r' option, which lets you specify the integer time to display, a la FreeBSD. The 'tzselect' command has two new options '-c' and '-n', which lets you select a zone based on latitude and longitude. The 'zic' command's '-v' option now warns about constructs that require the new version-3 binary file format. (Thanks to Arthur David Olson for the suggestion.) Support for floating-point time_t has been removed. It was always dicey, and POSIX no longer requires it. (Thanks to Eric Blake for suggesting to the POSIX committee to remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy Heninger, Arthur David Olson, and Alois Treindl, for reporting bugs and elucidating some of the corners of the old floating-point implementation.) The signatures of 'offtime', 'timeoff', and 'gtime' have been changed back to the old practice of using 'long' to represent UT offsets. This had been inadvertently and mistakenly changed to 'int_fast32_t'. (Thanks to Christos Zoulas.) The code avoids undefined behavior on integer overflow in some more places, including gmtime, localtime, mktime and zdump. Changes affecting the zdump utility zdump now outputs "UT" when referring to Universal Time, not "UTC".
d8fc842017-03-05Henrik Grubbström (Grubba)  "UTC" does not make sense for timestamps that predate the introduction
1e27ed2014-09-04Henrik Grubbström (Grubba)  of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen for clarifying UT vs UTC.) Data changes affecting behavior of tzselect and similar programs Country code BQ is now called the more-common name "Caribbean Netherlands" rather than the more-official "Bonaire, St Eustatius & Saba". Remove from zone.tab the names America/Montreal, America/Shiprock, and Antarctica/South_Pole, as they are equivalent to existing
d8fc842017-03-05Henrik Grubbström (Grubba)  same-country-code zones for post-1970 timestamps. The data entries for
1e27ed2014-09-04Henrik Grubbström (Grubba)  these names are unchanged, so the names continue to work as before. Changes affecting code internals zic -c now runs way faster on 64-bit hosts when given large numbers. zic now uses vfprintf to avoid allocating and freeing some memory. tzselect now computes the list of continents from the data, rather than have it hard-coded. Minor changes pacify GCC 4.7.3 and GCC 4.8.1. Changes affecting the build procedure The 'leapseconds' file is now generated automatically from a new file 'leap-seconds.list', which is a copy of
8de8e92017-11-17Henrik Grubbström (Grubba)  <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
1e27ed2014-09-04Henrik Grubbström (Grubba)  A new source file 'leapseconds.awk' implements this. The goal is simplification of the future maintenance of 'leapseconds'. When building the 'posix' or 'right' subdirectories, if the subdirectory would be a copy of the default subdirectory, it is now made a symbolic link if that is supported. This saves about 2 MB of file system space. The links America/Shiprock and Antarctica/South_Pole have been moved to the 'backward' file. This affects only nondefault builds that omit 'backward'. Changes affecting version-control only .gitignore now ignores 'date'. Changes affecting documentation and commentary Changes to the 'tzfile' man page It now mentions that the binary file format may be extended in future versions by appending data. It now refers to the 'zdump' and 'zic' man pages. Changes to the 'zic' man page It lists conditions that elicit a warning with '-v'. It says that the behavior is unspecified when duplicate names are given, or if the source of one link is the target of another. Its examples are updated to match the latest data. The definition of white space has been clarified slightly. (Thanks to Michael Deckers.) Changes to the 'Theory' file There is a new section about the accuracy of the tz database, describing the many ways that errors can creep in, and
d8fc842017-03-05Henrik Grubbström (Grubba)  explaining why so many of the pre-1970 timestamps are wrong or
1e27ed2014-09-04Henrik Grubbström (Grubba)  misleading (thanks to Steve Allen, Lester Caine, and Garrett Wollman for discussions that contributed to this). The 'Theory' file describes LMT better (this follows a suggestion by Guy Harris). It refers to the 2013 edition of POSIX rather than the 2004 edition. It's mentioned that excluding 'backward' should not affect the other data, and it suggests at least one zone.tab name per inhabited country (thanks to Stephen Colebourne). Some longstanding restrictions on names are documented, e.g., 'America/New_York' precludes 'America/New_York/Bronx'. It gives more reasons for the 1970 cutoff. It now mentions which time_t variants are supported, such as signed integer time_t. (Thanks to Paul Goyette for reporting typos in an experimental version of this change.) (Thanks to Philip Newton for correcting typos in these changes.) Documentation and commentary is more careful to distinguish UT in general from UTC in particular. (Thanks to Steve Allen.) Add a better source for the Zurich 1894 transition. (Thanks to Pierre-Yves Berger.) Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.) Release 2013d - 2013-07-05 07:38:01 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Morocco's midsummer transitions this year are July 7 and August 10, not July 9 and August 8. (Thanks to Andrew Paprocki.) Israel now falls back on the last Sunday of October. (Thanks to Ephraim Silverberg.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Specify Jerusalem's location more precisely; this changes the pre-1880 times by 2 s. Changing affecting metadata only: Fix typos in the entries for country codes BQ and SX. Changes affecting code: Rework the code to fix a bug with handling Australia/Macquarie on 32-bit hosts (thanks to Arthur David Olson). Port to platforms like NetBSD, where time_t can be wider than long. Add support for testing time_t types other than the system's. Run 'make check_time_t_alternatives' to try this out. Currently, the tests fail for unsigned time_t; this should get fixed at some point. Changes affecting documentation and commentary: Deemphasize the significance of national borders. Update the zdump man page. Remove obsolete NOID comment (thanks to Denis Excoffier). Update several URLs and comments in the web pages. Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler). Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka). Release 2013c - 2013-04-19 16:17:40 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting current and future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Palestine observed DST starting March 29, 2013. (Thanks to Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST, with the predicted rules being the last Thursday in March at 24:00 to the first Friday on or after September 21 at 01:00. Assume that the recent change to Paraguay's DST rules is permanent, by moving the end of DST to the 4th Sunday in March every year. (Thanks to Carlos Raúl Perasso.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting past timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Fix some historical data for Palestine to agree with that of timeanddate.com, as follows: The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not 00:00 Apr 1. The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not 02:00. The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27. The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2. The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01. The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00. Fix times of habitation for Macquarie to agree with the Tasmania Parks & Wildlife Service history, which indicates that permanent habitation was 1899-1919 and 1948 on. Changing affecting metadata only: Macquarie Island is politically part of Australia, not Antarctica. (Thanks to Tobias Conradi.) Sort Macquarie more-consistently with other parts of Australia. (Thanks to Tim Parenti.) Release 2013b - 2013-03-10 22:33:40 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting current and future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Haiti uses US daylight-saving rules this year, and presumably future years.
d8fc842017-03-05Henrik Grubbström (Grubba)  This changes timestamps starting today. (Thanks to Steffen Thorsen.)
1e27ed2014-09-04Henrik Grubbström (Grubba)  Paraguay will end DST on March 24 this year. (Thanks to Steffen Thorsen.) For now, assume it's just this year. Morocco does not observe DST during Ramadan; try to predict Ramadan in Morocco as best we can. (Thanks to Erik Homoet for the heads-up.) Changes affecting commentary: Update URLs in tz-link page. Add URLs for webOS, BB10, iOS. Update URL for Solaris. Mention Internet RFC 6557. Update Internet RFCs 2445->5545, 2822->5322. Switch from FTP to HTTP for Internet RFCs. Release 2013a - 2013-02-27 09:20:35 -0800 Change affecting binary data format: The zone offset at the end of version-2-format zone files is now allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes affecting current and future timestamps:
1e27ed2014-09-04Henrik Grubbström (Grubba)  Chile's 2013 rules, and we guess rules for 2014 and later, will be the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC. (Thanks to Steffen Thorsen and Robert Elz.) New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen. (Thanks to Tobias Conradi and Arthur David Olson.)
d8fc842017-03-05Henrik Grubbström (Grubba)  Many changes affect historical timestamps before 1940.
1e27ed2014-09-04Henrik Grubbström (Grubba)  These were deduced from: Milne J. Civil time. Geogr J. 1899
8de8e92017-11-17Henrik Grubbström (Grubba)  Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
1e27ed2014-09-04Henrik Grubbström (Grubba)  Changes affecting the code: Fix zic bug that mishandled Egypt's 2010 changes (this also affected the data). (Thanks to Arthur David Olson.) Fix localtime bug when time_t is unsigned and data files were generated by a signed time_t system. (Thanks to Doug Bailey for reporting and to Arthur David Olson for fixing.) Allow the email address for bug reports to be set by the packager. The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.) Update HTML checking to be compatible with Ubuntu 12.10. Check that files are a safe subset of ASCII. At some point we may relax this requirement to a safe subset of UTF-8. Without the check, some non-UTF-8 encodings were leaking into the distribution. Commentary changes: Restore a comment about copyright notices that was inadvertently deleted. (Thanks to Arthur David Olson.) Improve the commentary about which districts observe what times in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson). Add web page links to tz.js. Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.) Release 2012j - 2012-11-12 18:34:49 -0800 Libya moved to CET this weekend, but with DST planned next year. (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.) Signatures now have the extension .asc, not .sign, as that's more standard. (Thanks to Phil Pennock.) The output of 'zdump --version', and of 'zic --version', now uses a format that is more typical for --version. (Thanks to Joseph S. Myers.) The output of 'tzselect --help', 'zdump --help', and 'zic --help' now uses tz@iana.org rather than the old elsie address. zic -v now complains about abbreviations that are less than 3 or more than 6 characters, as per Posix. Formerly, it checked for abbreviations that were more than 3. 'make public' no longer puts its temporary directory under /tmp, and uses the just-built zic rather than the system zic. Various fixes to documentation and commentary. Release 2012i - 2012-11-03 12:57:09 -0700 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.) Linker flags can now be specified via LDFLAGS. AWK now defaults to 'awk', not 'nawk'. The shell in tzselect now defaults to /bin/bash, but this can be overridden by specifying KSHELL. The main web page now mentions the unofficial GitHub repository. (Thanks to Mike Frysinger.) Tarball signatures can now be built by running 'make signatures'. There are also new makefile rules 'tarballs', 'check_public', and separate makefile rules for each tarball and signature file. A few makefile rules are now more portable to strict POSIX. The main web page now lists the canonical IANA URL. Release 2012h - 2012-10-26 22:49:10 -0700 Bahia no longer has DST. (Thanks to Kelley Cook.) Tocantins has DST. (Thanks to Rodrigo Severo.) Israel has new DST rules next year. (Thanks to Ephraim Silverberg.) Jordan stays on DST this winter. (Thanks to Steffen Thorsen.) Web page updates. More C modernization, except that at Arthur David Olson's suggestion the instances of 'register' were kept. Release 2012g - 2012-10-17 20:59:45 -0700 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.) Palestine fall 2012. (Thanks to Steffen Thorsen.) Assume C89. To attack the version-number problem, this release ships the file 'Makefile' (which contains the release number) in both the tzcode and the tzdata tarballs. The two Makefiles are identical, and should be identical in any matching pair of tarballs, so it shouldn't matter which order you extract the tarballs. Perhaps we can come up with a better version-number scheme at some point; this scheme does have the virtue of not adding more files. Release 2012f - 2012-09-12 23:17:03 -0700 * australasia (Pacific/Fiji): Fiji DST is October 21 through January 20 this year. (Thanks to Steffen Thorsen.) Release 2012e - 2012-08-02 20:44:55 -0700
cca77d2016-10-23Henrik Grubbström (Grubba)  * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
1e27ed2014-09-04Henrik Grubbström (Grubba)  (Thanks to Steffen Thorsen.) * Use a single version number for both code and data. * .gitignore: New file. * Remove trailing white space. Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
d8fc842017-03-05Henrik Grubbström (Grubba)  Changes for Morocco's timestamps, which take effect in a couple of
1e27ed2014-09-04Henrik Grubbström (Grubba)  hours, along with infrastructure changes to accommodate how the tz code and data are released on IANA. Release data2012c - 2012-03-27 12:17:25 -0400 africa Summer time changes for Morocco (to start late April 2012) asia Changes for 2012 for Gaza & the West Bank (Hebron) and Syria northamerica Haiti following US/Canada rules for 2012 (and we're assuming, for now anyway, for the future). Release 2012b - 2012-03-02 12:29:15 +0700 There is just one change to tzcode2012b (compared with 2012a): the Makefile that was accidentally included with 2012a has been replaced with the version that should have been there, which is identical with the previous version (from tzcode2011i). There are just two changes in tzdata2012b compared with 2012a. Most significantly, summer time in Cuba has been delayed 3 weeks (now starts April 1 rather than March 11). Since Mar 11 (the old start date, as listed in 2012a) is just a little over a week away, this change is urgent. Less importantly, an excess tab in one of the changes in zone.tab in 2012a has been removed. Release 2012a - 2012-03-01 18:28:10 +0700 The changes in tzcode2012a (compared to the previous version, 2011i) are entirely to the README and tz-art.htm and tz-link.htm files, if none of those concern you, you can ignore the code update. The changes reflect the changed addresses for the mailing list and the code and data distribution points & methods (and a link to DateTime::TimeZone::Tzfile has been added to tz-link.htm). In tzdata2012a (compared to the previous release, which was 2011n) the major changes are: Chile 2011/2012 and 2012/2013 summer time date adjustments. Falkland Islands onto permanent summer time (we're assuming for the foreseeable future, though 2012 is all we're fairly certain of.) Armenia has abolished Summer Time. Tokelau jumped the International Date Line back last December (just the same as their near neighbour, Samoa). America/Creston is a new zone for a small area of British Columbia There will be a leapsecond 2012-06-30 23:59:60 UTC. Other minor changes are: Corrections to 1918 Canadian summer time end dates. Updated URL for UK time zone history (in comments) A few typos in Le Corre's list of free French place names (comments) Release data2011n - 2011-10-30 14:57:54 +0700 There are three changes of note - most urgently, Cuba (America/Havana) has extended summer time by two weeks, now to end on Nov 13, rather than the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic (Europe/Tiraspol) decided not to split from the rest of Moldova after all, and consequently that zone has been removed (again) and reinstated in the "backward" file as a link to Europe/Chisinau. And third, the end date for Fiji's summer time this summer was moved forward from the earlier planned Feb 26, to Jan 22. Apart from that, Moldova (MD) returns to a single entry in zone.tab (and the incorrect syntax that was in the 2011m version of that file is so fixed - it would have been fixed in a different way had this change not happened - that's the "missing" sccs version id). Release data2011m - 2011-10-24 21:42:16 +0700 In particular, the typos in comments in the data (2011-11-17 should have been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that Tim Parenti noted) have been fixed, and the change for Ukraine has been made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to Tim Parenti, and also Denys Gavrysh) In addition, I added Europe/Tiraspol to zone.tab. This time, all the files have new version numbers... (including the files otherwise unchanged in 2011m that were changed in 2011l but didn't get new version numbers there...) Release data2011l - 2011-10-10 11:15:43 +0700 There are just 2 changes that cause different generated tzdata files from zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil is included, but commented out. Compared with the diff I sent out last week, this version also includes attributions for the sources for the changes (in much the same format as ado used, but the html tags have not been checked, verified, or used in any way at all, so if there are errors there, please let me know.) Release data2011k - 2011-09-20 17:54:03 -0400 [not summarized] Release data2011j - 2011-09-12 09:22:49 -0400 (contemporary changes for Samoa; past changes for Kenya, Uganda, and Tanzania); there are also two spelling corrections to comments in the australasia file (with thanks to Christos Zoulas). Release 2011i - 2011-08-29 05:56:32 -0400 [not summarized] Release data2011h - 2011-06-15 18:41:48 -0400 Russia and Curaçao changes Release 2011g - 2011-04-25 09:07:22 -0400 update the rules for Egypt to reflect its abandonment of DST this year Release 2011f - 2011-04-06 17:14:53 -0400 [not summarized] Release 2011e - 2011-03-31 16:04:38 -0400 Morocco, Chile, and tz-link changes Release 2011d - 2011-03-14 09:18:01 -0400
d8fc842017-03-05Henrik Grubbström (Grubba)  changes that impact present-day timestamps in Cuba, Samoa, and Turkey
1e27ed2014-09-04Henrik Grubbström (Grubba)  Release 2011c - 2011-03-07 09:30:09 -0500
d8fc842017-03-05Henrik Grubbström (Grubba)  These do affect current timestamps in Chile and Annette Island, Canada.
1e27ed2014-09-04Henrik Grubbström (Grubba)  Release 2011b - 2011-02-07 08:44:50 -0500 [not summarized] Release 2011a - 2011-01-24 10:30:16 -0500 [not summarized] Release data2010o - 2010-11-01 09:18:23 -0400 change to the end of DST in Fiji in 2011 Release 2010n - 2010-10-25 08:19:17 -0400 [not summarized] Release 2010m - 2010-09-27 09:24:48 -0400 Hong Kong, Vostok, and zic.c changes Release 2010l - 2010-08-16 06:57:25 -0400 [not summarized] Release 2010k - 2010-07-26 10:42:27 -0400 [not summarized] Release 2010j - 2010-05-10 09:07:48 -0400 changes for Bahía de Banderas and for version naming Release data2010i - 2010-04-16 18:50:45 -0400 the end of DST in Morocco on 2010-08-08 Release data2010h - 2010-04-05 09:58:56 -0400 [not summarized] Release data2010g - 2010-03-24 11:14:53 -0400 [not summarized] Release 2010f - 2010-03-22 09:45:46 -0400 [not summarized] Release data2010e - 2010-03-08 14:24:27 -0500 corrects the Dhaka bug found by Danvin Ruangchan Release data2010d - 2010-03-06 07:26:01 -0500 [not summarized] Release 2010c - 2010-03-01 09:20:58 -0500 changes including KRE's suggestion for earlier initialization of "goahead" and "goback" structure elements Release code2010a - 2010-02-16 10:40:04 -0500 [not summarized] Release data2010b - 2010-01-20 12:37:01 -0500 Mexico changes Release data2010a - 2010-01-18 08:30:04 -0500 changes to Dhaka Release data2009u - 2009-12-26 08:32:28 -0500 changes to DST in Bangladesh Release 2009t - 2009-12-21 13:24:27 -0500 [not summarized] Release data2009s - 2009-11-14 10:26:32 -0500 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change Release 2009r - 2009-11-09 10:10:31 -0500 "antarctica" and "tz-link.htm" changes Release 2009q - 2009-11-02 09:12:40 -0500 with two corrections as reported by Eric Muller and Philip Newton Release data2009p - 2009-10-23 15:05:27 -0400 Argentina (including San Luis) changes (with the correction from Mariano Absatz) Release data2009o - 2009-10-14 16:49:38 -0400 Samoa (commentary only), Pakistan, and Bangladesh changes Release data2009n - 2009-09-22 15:13:38 -0400 added commentary for Argentina and a change to the end of DST in 2009 in Pakistan Release data2009m - 2009-09-03 10:23:43 -0400 Samoa and Palestine changes Release data2009l - 2009-08-14 09:13:07 -0400 Samoa (comments only) and Egypt Release 2009k - 2009-07-20 09:46:08 -0400 [not summarized] Release data2009j - 2009-06-15 06:43:59 -0400 Bangladesh change (with a short turnaround since the DST change is impending) Release 2009i - 2009-06-08 09:21:22 -0400 updating for DST in Bangladesh this year Release 2009h - 2009-05-26 09:19:14 -0400 [not summarized] Release data2009g - 2009-04-20 16:34:07 -0400 Cairo Release data2009f - 2009-04-10 11:00:52 -0400 correct DST in Pakistan Release 2009e - 2009-04-06 09:08:11 -0400 [not summarized] Release 2009d - 2009-03-23 09:38:12 -0400 Morocco, Tunisia, Argentina, and American Astronomical Society changes Release data2009c - 2009-03-16 09:47:51 -0400 change to the start of Cuban DST Release 2009b - 2009-02-09 11:15:22 -0500 [not summarized] Release 2009a - 2009-01-21 10:09:39 -0500 [not summarized] Release data2008i - 2008-10-21 12:10:25 -0400 southamerica and zone.tab files, with Argentina DST rule changes and United States zone reordering and recommenting Release 2008h - 2008-10-13 07:33:56 -0400 [not summarized] Release 2008g - 2008-10-06 09:03:18 -0400 Fix a broken HTML anchor and update Brazil's DST transitions; there's also a slight reordering of information in tz-art.htm. Release data2008f - 2008-09-09 22:33:26 -0400 [not summarized] Release 2008e - 2008-07-28 14:11:17 -0400 changes by Arthur David Olson and Jesper Nørgaard Welen Release data2008d - 2008-07-07 09:51:38 -0400 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo Release data2008c - 2008-05-19 17:48:03 -0400 Pakistan, Morocco, and Mongolia Release data2008b - 2008-03-24 08:30:59 -0400 including renaming Asia/Calcutta to Asia/Kolkata, with a backward link provided Release 2008a - 2008-03-08 05:42:16 -0500 [not summarized] Release 2007k - 2007-12-31 10:25:22 -0500 most importantly, changes to the "southamerica" file based on Argentina's readoption of daylight saving time Release 2007j - 2007-12-03 09:51:01 -0500 1. eliminate the "P" (parameter) macro; 2. the "noncontroversial" changes circulated on the time zone mailing list (less the changes to "logwtmp.c"); 3. eliminate "too many transition" errors when "min" is used in time zone rules; 4. changes by Paul Eggert (including updated information for Venezuela). Release data2007i - 2007-10-30 10:28:11 -0400 changes for Cuba and Syria Release 2007h - 2007-10-01 10:05:51 -0400 changes by Paul Eggert, as well as an updated link to the ICU project in tz-link.htm Release 2007g - 2007-08-20 10:47:59 -0400 changes by Paul Eggert The "leapseconds" file has been updated to incorporate the most recent International Earth Rotation and Reference Systems Service (IERS) bulletin. There's an addition to tz-art.htm regarding the television show "Medium". Release 2007f - 2007-05-07 10:46:46 -0400 changes by Paul Eggert (including Haiti, Turks and Caicos, and New Zealand) changes to zic.c to allow hour values greater than 24 (along with Paul's improved time value overflow checking) Release 2007e - 2007-04-02 10:11:52 -0400 Syria and Honduras changes by Paul Eggert zic.c variable renaming changes by Arthur David Olson Release 2007d - 2007-03-20 08:48:30 -0400 changes by Paul Eggert the elimination of white space at the ends of lines Release 2007c - 2007-02-26 09:09:37 -0500 changes by Paul Eggert Release 2007b - 2007-02-12 09:34:20 -0500 Paul Eggert's proposed change to the quotation handling logic in zic.c. changes to the commentary in "leapseconds" reflecting the IERS announcement that there is to be no positive leap second at the end of June 2007. Release 2007a - 2007-01-08 12:28:29 -0500 changes by Paul Eggert Derick Rethan's Asmara change Oscar van Vlijmen's Easter Island local mean time change symbolic link changes Release 2006p - 2006-11-27 08:54:27 -0500 changes by Paul Eggert Release 2006o - 2006-11-06 09:18:07 -0500 changes by Paul Eggert Release 2006n - 2006-10-10 11:32:06 -0400 changes by Paul Eggert Release 2006m - 2006-10-02 15:32:35 -0400 changes for Uruguay, Palestine, and Egypt by Paul Eggert (minimalist) changes to zic.8 to clarify "until" information Release data2006l - 2006-09-18 12:58:11 -0400 Paul's best-effort work on this coming weekend's Egypt time change Release 2006k - 2006-08-28 12:19:09 -0400 changes by Paul Eggert Release 2006j - 2006-08-21 09:56:32 -0400 changes by Paul Eggert Release code2006i - 2006-08-07 12:30:55 -0400 localtime.c fixes Ken Pizzini's conversion script Release code2006h - 2006-07-24 09:19:37 -0400 adds public domain notices to four files includes a fix for transition times being off by a second adds a new recording to the "arts" file (information courtesy Colin Bowern) Release 2006g - 2006-05-08 17:18:09 -0400 northamerica changes by Paul Eggert Release 2006f - 2006-05-01 11:46:00 -0400 a missing version number problem is fixed (with thanks to Bradley White for catching the problem) Release 2006d - 2006-04-17 14:33:43 -0400 changes by Paul Eggert added new items to tz-arts.htm that were found by Paul Release 2006c - 2006-04-03 10:09:32 -0400 two sets of data changes by Paul Eggert a fencepost error fix in zic.c changes to zic.c and the "europe" file to minimize differences between output produced by the old 32-bit zic and the new 64-bit version Release 2006b - 2006-02-20 10:08:18 -0500 [tz32code2006b + tz64code2006b + tzdata2006b] 64-bit code All SCCS IDs were bumped to "8.1" for this release. Release 2006a - 2006-01-30 08:59:31 -0500 changes by Paul Eggert (in particular, Indiana time zone moves) an addition to the zic manual page to describe how special-case transitions are handled Release 2005r - 2005-12-27 09:27:13 -0500 Canadian changes by Paul Eggert They also add "<pre>" directives to time zone data files and reflect changes to warning message logic in "zdump.c" (but with calls to "gettext" kept unbundled at the suggestion of Ken Pizzini). Release 2005q - 2005-12-13 09:17:09 -0500 Nothing earth-shaking here: 1. Electronic mail addresses have been removed. 2. Casts of the return value of exit have been removed. 3. Casts of the argument of is.* macros have been added. 4. Indentation in one section of zic.c has been fixed. 5. References to dead URLs in the data files have been dealt with. Release 2005p - 2005-12-05 10:30:53 -0500 "systemv", "tz-link.htm", and "zdump.c" changes (less the casts of arguments to the is* macros) Release 2005o - 2005-11-28 10:55:26 -0500 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert zdump.c lint fixes by Arthur David Olson Release 2005n - 2005-10-03 09:44:09 -0400 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan et al. changes) Release 2005m - 2005-08-29 12:15:40 -0400 changes by Paul Eggert (with a small tweak to the tz-art change) a declaration of an unused variable has been removed from zdump.c Release 2005l - 2005-08-22 12:06:39 -0400 changes by Paul Eggert overflow/underflow checks by Arthur David Olson, minus changes to the "Theory" file about the pending addition of 64-bit data (I grow less confident of the changes being accepted with each passing day, and the changes no longer increase the data files nine-fold--there's less than a doubling in size by my local Sun's reckoning) Release 2005k - 2005-07-14 14:14:24 -0400 The "leapseconds" file has been edited to reflect the recently announced leap second at the end of 2005. I've also deleted electronic mail addresses from the files as an anti-spam measure. Release 2005j - 2005-06-13 14:34:13 -0400 These reflect changes to limit the length of time zone abbreviations and the characters used in those abbreviations.
b401d62018-12-18Henrik Grubbström (Grubba)  There are also changes to handle POSIX-style "quoted" timezone
1e27ed2014-09-04Henrik Grubbström (Grubba)  environment variables. The changes were circulated on the time zone mailing list; the only change since then was the removal of a couple of minimum-length of abbreviation checks. Release data2005i - 2005-04-21 15:04:16 -0400 changes (most importantly to Nicaragua and Haiti) by Paul Eggert Release 2005h - 2005-04-04 11:24:47 -0400 changes by Paul Eggert minor changes to Makefile and zdump.c to produce more useful output when doing a "make typecheck" Release 2005g - 2005-03-14 10:11:21 -0500 changes by Paul Eggert (a change to current DST rules in Uruguay and an update to a link to time zone software) Release 2005f - 2005-03-01 08:45:32 -0500 data and documentation changes by Paul Eggert Release 2005e - 2005-02-10 15:59:44 -0500 [not summarized] Release code2005d - 2005-01-31 09:21:47 -0500 make zic complain about links to links if the -v flag is used have "make public" do more code checking add an include to "localtime.c" for the benefit of gcc systems Release 2005c - 2005-01-17 18:36:29 -0500 get better results when mktime runs on a system where time_t is double changes to the data files (most importantly to Paraguay) Release 2005b - 2005-01-10 09:19:54 -0500 Get localtime and gmtime working on systems with exotic time_t types. Update the leap second commentary in the "leapseconds" file. Release 2005a - 2005-01-01 13:13:44 -0500 [not summarized] Release code2004i - 2004-12-14 13:42:58 -0500 Deal with systems where time_t is unsigned. Release code2004h - 2004-12-07 11:40:18 -0500 64-bit-time_t changes Release 2004g - 2004-11-02 09:06:01 -0500 update to Cuba (taking effect this weekend) other changes by Paul Eggert correction of the spelling of Oslo changed versions of difftime.c and private.h Release code2004f - 2004-10-21 10:25:22 -0400 Cope with wide-ranging tm_year values. Release 2004e - 2004-10-11 14:47:21 -0400 Brazil/Argentina/Israel changes by Paul Eggert changes to tz-link.htm by Paul one small fix to Makefile Release 2004d - 2004-09-22 08:27:29 -0400 Avoid overflow problems when TM_YEAR_BASE is added to an integer. Release 2004c - 2004-08-11 12:06:26 -0400 asctime-related changes (variants of) some of the documentation changes suggested by Paul Eggert Release 2004b - 2004-07-19 14:33:35 -0400 data changes by Paul Eggert - most importantly, updates for Argentina Release 2004a - 2004-05-27 12:00:47 -0400 changes by Paul Eggert Handle DST transitions that occur at the end of a month in some years but at the start of the following month in other years. Add a copy of the correspondence that's the basis for claims about DST in the Navajo Nation. Release 2003e - 2003-12-15 09:36:47 -0500 changes by Arthur David Olson (primarily code changes) changes by Paul Eggert (primarily data changes) minor changes to "Makefile" and "northamerica" (in the latter case, optimization of the "Toronto" rules) Release 2003d - 2003-10-06 09:34:44 -0400 changes by Paul Eggert Release 2003c - 2003-09-16 10:47:05 -0400 Fix bad returns in zic.c's inleap function. Thanks to Bradley White for catching the problem! Release 2003b - 2003-09-16 07:13:44 -0400 Add a "--version" option (and documentation) to the zic and zdump commands. changes to overflow/underflow checking in zic a localtime typo fix. Update the leapseconds and tz-art.htm files. Release 2003a - 2003-03-24 09:30:54 -0500 changes by Paul Eggert a few additions and modifications to the tz-art.htm file Release 2002d - 2002-10-15 13:12:42 -0400 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab There's also a new time zone quote in "tz-art.htm". Release 2002c - 2002-04-04 11:55:20 -0500 changes by Paul Eggert Change zic.c to avoid creating symlinks to files that don't exist. Release 2002b - 2002-01-28 12:56:03 -0500 [These change notes are for Release 2002a, which was corrupted. 2002b was a corrected version of 2002a.] changes by Paul Eggert Update the "leapseconds" file to note that there'll be no leap second at the end of June, 2002. Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone. Change to "difftime.c" to avoid sizeof problems. Release 2001d - 2001-10-09 13:31:32 -0400 changes by Paul Eggert Release 2001c - 2001-06-05 13:59:55 -0400 changes by Paul Eggert and Andrew Brown Release 2001b - 2001-04-05 16:44:38 -0400 changes by Paul Eggert (modulo jnorgard's typo fix) tz-art.htm has been HTMLified. Release 2001a - 2001-03-13 12:57:44 -0500 changes by Paul Eggert An addition to the "leapseconds" file: comments with the text of the latest IERS leap second notice. Trailing white space has been removed from data file lines, and repeated spaces in "Rule Jordan" lines in the "asia" file have been converted to tabs. Release 2000h - 2000-12-14 15:33:38 -0500 changes by Paul Eggert one typo fix in the "art" file With providence, this is the last update of the millennium. Release 2000g - 2000-10-10 11:35:22 -0400 changes by Paul Eggert correction of John Mackin's name submitted by Robert Elz Garry Shandling's Daylight Saving Time joke (!?!) from the recent Emmy Awards broadcast. Release 2000f - 2000-08-10 09:31:58 -0400 changes by Paul Eggert Added information in "tz-art.htm" on a Seinfeld reference to DST. Error checking and messages in the "yearistype" script have been improved. Release 2000e - 2000-07-31 09:27:54 -0400 data changes by Paul Eggert a change to the default value of the defined constant HAVE_STRERROR the addition of a Dave Barry quote on DST to the tz-arts file Release 2000d - 2000-04-20 15:43:04 -0400 changes to the documentation and code of strftime for C99 conformance a bug fix for date.c These are based on (though modified from) changes by Paul Eggert. Release 2000c - 2000-03-04 10:31:43 -0500 changes by Paul Eggert Release 2000b - 2000-02-21 12:16:29 -0500 changes by Paul Eggert and Joseph Myers modest tweaks to the tz-art.htm and tz-link.htm files Release 2000a - 2000-01-18 09:21:26 -0500 changes by Paul Eggert The two hypertext documents have also been renamed. Release code1999i-data1999j - 1999-11-15 18:43:22 -0500 Paul Eggert's changes additions to the "zic" manual page and the "Arts.htm" file Release code1999h-data1999i - 1999-11-08 14:55:21 -0500 [not summarized] Release data1999h - 1999-10-07 03:50:29 -0400 changes by Paul Eggert to "europe" (most importantly, fixing Lithuania and Estonia) Release 1999g - 1999-09-28 11:06:18 -0400 data changes by Paul Eggert (most importantly, the change for Lebanon that buys correctness for this coming Sunday) The "code" file contains changes to "Makefile" and "checktab.awk" to allow better checking of time zone files before they are published. Release 1999f - 1999-09-23 09:48:14 -0400 changes by Arthur David Olson and Paul Eggert Release 1999e - 1999-08-17 15:20:54 -0400 changes circulated by Paul Eggert, although the change to handling
b401d62018-12-18Henrik Grubbström (Grubba)  of DST-specifying timezone names has been commented out for now
1e27ed2014-09-04Henrik Grubbström (Grubba)  (search for "XXX" in "localtime.c" for details). These files also do not make any changes to the start of DST in Brazil. In addition to Paul's changes, there are updates to "Arts.htm" and cleanups of URLs. Release 1999d - 1999-03-30 11:31:07 -0500 changes by Paul Eggert The Makefile's "make public" rule has also been changed to do a test compile of each individual time zone data file (which should help avoid problems such as the one we had with Nicosia). Release 1999c - 1999-03-25 09:47:47 -0500 changes by Paul Eggert, most importantly the change for Chile. Release 1999b - 1999-02-01 17:51:44 -0500 changes by Paul Eggert code changes (suggested by Mani Varadarajan, mani at be.com) for correct handling of symbolic links when building using a relative directory code changes to generate correct messages for failed links updates to the URLs in Arts.htm Release 1999a - 1999-01-19 16:20:29 -0500 error message internationalizations and corrections in zic.c and zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz, to whom thanks!) Release code1998h-data1998i - 1998-10-01 09:56:10 -0400 changes for Brazil, Chile, and Germany support for use of "24:00" in the input files for the time zone compiler Release code1998g-data1998h - 1998-09-24 10:50:28 -0400 changes by Paul Eggert correction to a define in the "private.h" file Release data1998g - 1998-08-11 03:28:35 -0000 [tzdata1998g.tar.gz is missing!] Lithuanian change provided by mgedmin at pub.osf.it Move creation of the GMT link with Etc/GMT to "etcetera" (from "backward") to ensure that the GMT file is created even where folks don't want the "backward" links (as suggested by Paul Eggert). Release data1998f - 1998-07-20 13:50:00 -0000 [tzdata1998f.tar.gz is missing!] Update the "leapseconds" file to include the newly-announced insertion at the end of 1998. Release code1998f - 1998-06-01 10:18:31 -0400 addition to localtime.c by Guy Harris Release 1998e - 1998-05-28 09:56:26 -0400 The Makefile is changed to produce zoneinfo-posix rather than zoneinfo/posix, and to produce zoneinfo-leaps rather than zoneinfo/right. data changes by Paul Eggert changes from Guy Harris to provide asctime_r and ctime_r A usno1998 file (substantially identical to usno1997) has been added. Release 1998d - 1998-05-14 11:58:34 -0400 changes to comments (in particular, elimination of references to CIA maps). "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places where changes occur. Release 1998c - 1998-02-28 12:32:26 -0500 changes by Paul Eggert (save the "French correction," on which I'll wait for the dust to settle) symlink changes changes and additions to Arts.htm Release 1998b - 1998-01-17 14:31:51 -0500 URL cleanups and additions Release 1998a - 1998-01-13 12:37:35 -0500 changes by Paul Eggert Release code1997i-data1997k - 1997-12-29 09:53:41 -0500 changes by Paul Eggert, with minor modifications from Arthur David Olson to make the files more browser friendly Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
b401d62018-12-18Henrik Grubbström (Grubba)  minor changes to put "TZif" at the start of each timezone information file
1e27ed2014-09-04Henrik Grubbström (Grubba)  a rule has also been added to the Makefile so you can make zones to just recompile the zone information files (rather than doing a full "make install" with its other effects). Release data1997i - 1997-10-07 08:45:38 -0400 changes to Africa by Paul Eggert Release code1997g-data1997h - 1997-09-04 16:56:54 -0400 corrections for Uruguay (and other locations) Arthur David Olson's simple-minded fix allowing mktime to both correctly handle leap seconds and correctly handle tm_sec values upon which arithmetic has been performed. Release code1997f-data1997g - 1997-07-19 13:15:02 -0400 Paul Eggert's updates a small change to a function prototype; "Music" has been renamed "Arts.htm", HTMLified, and augmented to include information on Around the World in Eighty Days. Release code1997e-data1997f - 1997-05-03 18:52:34 -0400 fixes to zic's error handling changes inspired by the item circulated on Slovenia The description of Web resources has been HTMLified for browsing convenience. A new piece of tz-related music has been added to the "Music" file. Release code1997d-data1997e - 1997-03-29 12:48:52 -0500 Paul Eggert's latest suggestions Release code1997c-data1997d - 1997-03-07 20:37:54 -0500 changes to "zic.c" to correct performance of the "-s" option a new file "usno1997" Release data1997c - 1997-03-04 09:58:18 -0500 changes in Israel Release 1997b - 1997-02-27 18:34:19 -0500 The data file incorporates the 1997 leap second. The code file incorporates Arthur David Olson's take on the zic/multiprocessor/directory-creation situation. Release 1997a - 1997-01-21 09:11:10 -0500 Paul Eggert's Antarctica (and other changes) Arthur David Olson finessed the "getopt" issue by checking against both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1 is returned while SunOS 5.5's manual says EOF is returned). Release code1996o-data1996n - 1996-12-27 21:42:05 -0500 Paul Eggert's latest changes Release code1996n - 1996-12-16 09:42:02 -0500 link snapping fix from Bruce Evans (via Garrett Wollman) Release data1996m - 1996-11-24 02:37:34 -0000 [tzdata1996m.tar.gz is missing!] Paul Eggert's batch of changes Release code1996m-data1996l - 1996-11-05 14:00:12 -0500 No functional changes here; the files have simply been changed to make more use of ISO style dates in comments. The names of the above files now include the year in full. Release code96l - 1996-09-08 17:12:20 -0400 tzcode96k was missing a couple of pieces. Release 96k - 1996-09-08 16:06:22 -0400 the latest round of changes from Paul Eggert the recent Year 2000 material Release code96j - 1996-07-30 13:18:53 -0400 Set sp->typecnt as suggested by Timothy Patrick Murphy. Release code96i - 1996-07-27 20:11:35 -0400 Paul's suggested patch for strftime %V week numbers Release data96i - 1996-07-01 18:13:04 -0400 "northamerica" and "europe" changes by Paul Eggert Release code96h - 1996-06-05 08:02:21 -0400 fix for handling transitions specified in Universal Time Some "public domain" notices have also been added. Release code96g - 1996-05-16 14:00:26 -0400 fix for the simultaneous-DST-and-zone-change challenge Release data96h - 1996-05-09 17:40:51 -0400 changes by Paul Eggert Release code96f-data96g - 1996-05-03 03:09:59 -0000 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!] The changes get us some of the way to fixing the problems noted in Paul Eggert's letter yesterday (in addition to a few others). The approach has been to make zic a bit smarter about figuring out what time zone abbreviations apply just after the time specified in the "UNTIL" part of a zone line. Putting the smarts in zic means avoiding having transition times show up in both "Zone" lines and "Rule" lines, which in turn avoids multiple transition time entries in time zone files. (This also makes the zic input files such as "europe" a bit shorter and should ease maintenance.) Release data96f - 1996-04-19 19:20:03 -0000 [tzdata96f.tar.gz is missing!] The only changes are to the "northamerica" file; the time zone abbreviation for Denver is corrected to MST (and MDT), and the comments for Mexico have been updated. Release data96e - 1996-03-19 17:37:26 -0500 Proposals by Paul Eggert, in particular the Portugal change that comes into play at the end of this month. Release data96d - 1996-03-18 20:49:39 -0500 [not summarized] Release code96e - 1996-02-29 15:43:27 -0000 [tzcode96e.tar.gz is missing!] internationalization changes and the fix to the documentation for strftime Release code96d-data96c - 1996-02-12 11:05:27 -0500 The "code" file simply updates Bob Kridle's electronic address. The "data" file updates rules for Mexico. Release data96b - 1996-01-27 15:44:42 -0500 Kiribati change Release code96c - 1996-01-16 16:58:15 -0500 leap-year streamlining and binary-search changes fix to newctime.3 Release code96b - 1996-01-10 20:42:39 -0500 fixes and enhancements from Paul Eggert, including code that emulates the behavior of recent versions of the SunOS "date" command. Release 96a - 1996-01-06 09:08:24 -0500 Israel updates fixes to strftime.c for correct ISO 8601 week number generation, plus support for two new formats ('G' and 'g') to give ISO 8601 year numbers (which are not necessarily the same as calendar year numbers) Release code95i-data95m - 1995-12-21 12:46:47 -0500 The latest revisions from Paul Eggert are included, the usno1995 file has been updated, and a new file ("WWW") covering useful URLs has been added. Release code95h-data95l - 1995-12-19 18:10:12 -0500 A simplification of a macro definition, a change to data for Sudan, and (for last minute shoppers) notes in the "Music" file on the CD "Old Man Time". Release code95g-data95k - 1995-10-30 10:32:47 -0500 (slightly reformatted) 8-bit-clean proposed patch minor patch: US/Eastern -> America/New_York snapshot of the USNO's latest data ("usno1995") some other minor cleanups Release code95f-data95j - 1995-10-28 21:01:34 -0000 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!] European cleanups support for 64-bit time_t's optimization in localtime.c Release code95e - 1995-10-13 13:23:57 -0400 the mktime change to scan from future to past when trying to find time zone offsets Release data95i - 1995-09-26 10:43:26 -0400 For Canada/Central, guess that the Sun customer's "one week too early" was just a approximation, and the true error is one month too early. This is consistent with the rest of Canada. Release data95h - 1995-09-21 11:26:48 -0400 latest changes from Paul Eggert Release code95d - 1995-09-14 11:14:45 -0400 the addition of a "Music" file, which documents four recorded versions of the tune "Save That Time". Release data95g - 1995-09-01 17:21:36 -0400 "yearistype" correction Release data95f - 1995-08-28 20:46:56 -0400 Paul Eggert's change to the australasia file Release data95e - 1995-07-08 18:02:34 -0400 The only change is a leap second at the end of this year. Thanks to Bradley White for forwarding news on the leap second. Release data95d - 1995-07-03 13:26:22 -0400 Paul Eggert's changes Release data95c - 1995-07-02 19:19:28 -0400 changes to "asia", "backward", "europe", and "southamerica" (read: northamericacentrics need not apply) Release code95c - 1995-03-13 14:00:46 -0500 one-line fix for sign extension problems in detzcode Release 95b - 1995-03-04 11:22:38 -0500 Minor changes in both: The "code" file contains a workaround for the lack of "unistd.h" in Microsoft C++ version 7. The "data" file contains a fixed "Link" for America/Shiprock. Release 94h - 1994-12-10 12:51:14 -0500 The files: * incorporate the changes to "zdump" and "date" to make changes to the "TZ" environment variable permanent; * incorporate the table changes by Paul Eggert; * include (and document) support for universal time specifications in data files - but do not (yet) include use of this feature in the data files. Think of this as "TZ Classic" - the software has been set up not to break if universal time shows up in its input, and data entries have been left as is so as not to break existing implementations. Release data94f - 1994-08-20 12:56:09 -0400 (with thanks!) the latest data updates from Paul Eggert Release data94e - 1994-06-04 13:13:53 -0400 [not summarized] Release code94g - 1994-05-05 12:14:07 -0400 fix missing "optind.c" and a reference to it in the Makefile Release code94f - 1994-05-05 13:00:33 -0000 [tzcode94f.tar.gz is missing!] changes to avoid overflow in difftime, as well as changes to cope with the 52/53 challenge in strftime Release code94e - 1994-03-30 23:32:59 -0500 change for the benefit of PCTS Release 94d - 1994-02-24 15:42:25 -0500 Avoid clashes with POSIX semantics for zones such as GMT+4. Some other very minor housekeeping is also present. Release code94c - 1994-02-10 08:52:40 -0500 Fix bug where mkdirs was broken unless you compile with -fwritable-strings (which is generally losing to do). Release 94b - 1994-02-07 10:04:33 -0500 work by Paul Eggert who notes: I found another book of time zone histories by E W Whitman; it's not as extensive as Shanks but has a few goodies of its own. I used it to update the tables. I also fixed some more as a result of correspondence with Adam David and Peter Ilieve, and move some stray links from 'europe' to 'backward'. I corrected some scanning errors in usno1989. As far as the code goes, I fixed zic to allow years in the range INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900. And I cleaned up the zic documentation a little bit. Release data94a - 1994-02-03 08:58:54 -0500 It simply incorporates the recently announced leap second into the "leapseconds" file. Release 93g - 1993-11-22 17:28:27 -0500 Paul Eggert has provided a good deal of historic information (based on Shanks), and there are some code changes to deal with the buglets that crawled out in dealing with the new information. Release 93f - 1993-10-15 12:27:46 -0400 Paul Eggert's changes Release 93e - 1993-09-05 21:21:44 -0400 This has updated data for Israel, England, and Kwajalein. There's also an update to "zdump" to cope with Kwajalein's 24-hour jump. Thanks to Paul Eggert and Peter Ilieve for the changes. Release 93d - 1993-06-17 23:34:17 -0400 new fix and new data on Israel Release 93c - 1993-06-06 19:31:55 -0400 [not summarized] Release 93b - 1993-02-02 14:53:58 -0500 updated "leapseconds" file Release 93 - 1993-01-08 07:01:06 -0500 At kre's suggestion, the package has been split in two - a code piece (which also includes documentation) that's only of use to folks who want to recompile things and a data piece useful to anyone who can run "zic". The new version has a few changes to the data files, a few portability changes, and an off-by-one fix (with thanks to Tom Karzes at deshaw.com for providing a description and a solution). Release 92c - 1992-11-21 17:35:36 -0000 [tz92c.tar.Z is missing!] The fallout from the latest round of DST transitions. There are changes for Portugal, Saskatchewan, and "Pacific-New"; there's also a change to "zic.c" that makes it portable to more systems. Release 92 - 1992-04-25 18:17:03 -0000 [tz92.tar.Z is missing!] By popular demand (well, at any rate, following a request by kre at munnari) The 1989 update of the time zone package featured: * POSIXization (including interpretation of POSIX-style TZ environment variables, provided by Guy Harris), * ANSIfication (including versions of "mktime" and "difftime"), * SVIDulation (an "altzone" variable) * MACHination (the "gtime" function) * corrections to some time zone data (including corrections to the rules for Great Britain and New Zealand) * reference data from the United States Naval Observatory for folks who want to do additional time zones * and the 1989 data for Saudi Arabia. (Since this code will be treated as "part of the implementation" in some places and as "part of the application" in others, there's no good way to name functions, such as timegm, that are not part of the proposed ANSI C standard; such functions have kept their old, underscore-free names in this update.) And the "dysize" function has disappeared; it was present to allow compilation of the "date" command on old BSD systems, and a version of "date" is now provided in the package. The "date" command is not created when you "make all" since it may lack options provided by the version distributed with your operating system, or may not interact with the system in the same way the native version does. Since POSIX frowns on correct leap second handling, the default behavior of the "zic" command (in the absence of a "-L" option) has been changed to omit leap second information from its output files. ----- Notes This file contains copies of the part of each release announcement that talks about the changes in that release. The text has been adapted and reformatted for the purposes of this file.
cca77d2016-10-23Henrik Grubbström (Grubba) Traditionally a release R consists of a pair of tarball files,
1e27ed2014-09-04Henrik Grubbström (Grubba) tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g., code2010a, data2012c) consist of just one or the other tarball, and a few (e.g., code2012c-data2012d) have tarballs with mixed version
cca77d2016-10-23Henrik Grubbström (Grubba) numbers. Recent releases also come in an experimental format consisting of a single tarball tzdb-R.tar.lz with extra data.
1e27ed2014-09-04Henrik Grubbström (Grubba) 
d8fc842017-03-05Henrik Grubbström (Grubba) Release timestamps are taken from the release's commit (for newer,
cca77d2016-10-23Henrik Grubbström (Grubba) Git-based releases), from the newest file in the tarball (for older
1e27ed2014-09-04Henrik Grubbström (Grubba) releases, where this info is available) or from the email announcing
b401d62018-12-18Henrik Grubbström (Grubba) the release (if all else fails; these are marked with a time zone abbreviation of -0000 and an "is missing!" comment).
1e27ed2014-09-04Henrik Grubbström (Grubba)  Earlier versions of the code and data were not announced on the tz list and are not summarized here. This file is in the public domain. Local Variables: coding: utf-8 End: