The Time Zone Database (often called tz or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules. Here is a recipe for acquiring, building, installing, and testing the tz distribution on a GNU/Linux or similar host.
To acquire the distribution, run the following shell commands:
mkdir tz cd tz wget --retr-symlinks 'ftp://ftp.iana.org/tz/tz*-latest.tar.gz' gzip -dc tzcode-latest.tar.gz | tar -xf - gzip -dc tzdata-latest.tar.gz | tar -xf -
Alternatively, the following shell commands acquire the same
distribution, with extra data useful for regression testing:
wget --retr-symlinks 'ftp://ftp.iana.org/tz/tzdb-latest.tar.lz'
lzip -dc tzdb-latest.tar.lz | tar -xf -
Be sure to read the comments in "Makefile" and make any changes needed to make things right for your system, especially if you are using some platform other than GNU/Linux. Then run the following commands, substituting your desired installation directory for "$HOME/tzdir": make TOPDIR=$HOME/tzdir install $HOME/tzdir/etc/zdump -v America/Los_Angeles Historical local time information has been included here to: