9cef64 2014-10-16 Henrik GrubbstrĂ¶m (Grubba) # Generate the 'leapseconds' file from 'leap-seconds.list'. # This file is in the public domain. BEGIN { print "# Allowance for leap seconds added to each time zone file." print "" print "# This file is in the public domain." print "" print "# This file is generated automatically from the data in the public-domain" print "# leap-seconds.list file available from most NIST time servers." print "# If the URL does not work," print "# you should be able to pick up leap-seconds.list from a secondary NIST server." print "# For more about leap-seconds.list, please see" print "# The NTP Timescale and Leap Seconds" print "# http://www.eecis.udel.edu/~mills/leap.html" print "" print "# The International Earth Rotation Service periodically uses leap seconds" print "# to keep UTC to within 0.9 s of UT1" print "# (which measures the true angular orientation of the earth in space); see" print "# Terry J Quinn, The BIPM and the accurate measure of time," print "# Proc IEEE 79, 7 (July 1991), 894-905 ." print "# There were no leap seconds before 1972, because the official mechanism" print "# accounting for the discrepancy between atomic time and the earth's rotation" print "# did not exist until the early 1970s." print "" print "# The correction (+ or -) is made at the given time, so lines" print "# will typically look like:" print "# Leap YEAR MON DAY 23:59:60 + R/S" print "# or" print "# Leap YEAR MON DAY 23:59:59 - R/S" print "" print "# If the leapsecond is Rolling (R) the given time is local time." print "# If the leapsecond is Stationary (S) the given time is UTC." print "" print "# Leap YEAR MONTH DAY HH:MM:SS CORR R/S" } /^ *\$/ { next } /^#/ { next } { NTP_timestamp = \$1 TAI_minus_UTC = \$2 hash_mark = \$3 one = \$4 month = \$5 year = \$6 if (old_TAI_minus_UTC) { if (old_TAI_minus_UTC < TAI_minus_UTC) { sign = "23:59:60\t+" } else { sign = "23:59:59\t-" } if (month == "Jan") { year--; month = "Dec"; day = 31 } else if (month == "Jul") { month = "Jun"; day = 30 } printf "Leap\t%s\t%s\t%s\t%s\tS\n", year, month, day, sign } old_TAI_minus_UTC = TAI_minus_UTC }