1README for the tz distribution 2 3"What time is it?" -- Richard Deacon as The King 4"Any time you want it to be." -- Frank Baxter as The Scientist 5 (from the Bell System film "About Time") 6 7The Time Zone Database (often called tz or zoneinfo) contains code and 8data that represent the history of local time for many representative 9locations around the globe. It is updated periodically to reflect 10changes made by political bodies to time zone boundaries, UTC offsets, 11and daylight-saving rules. 12 13Unless otherwise specified, all files in the tz code and data are in 14the public domain, so clarified as of 2009-05-17 by Arthur David Olson. 15The few exceptions are code derived from BSD, which uses the BSD license. 16 17Here is a recipe for acquiring, building, installing, and testing the 18tz distribution on a GNU/Linux or similar host. 19 20 mkdir tz 21 cd tz 22 wget --retr-symlinks 'ftp://ftp.iana.org/tz/tz*-latest.tar.gz' 23 gzip -dc tzcode-latest.tar.gz | tar -xf - 24 gzip -dc tzdata-latest.tar.gz | tar -xf - 25 26Be sure to read the comments in "Makefile" and make any changes needed 27to make things right for your system, especially if you are using some 28platform other than GNU/Linux. Then run the following commands, 29substituting your desired installation directory for "$HOME/tzdir": 30 31 make TOPDIR=$HOME/tzdir install 32 $HOME/tzdir/etc/zdump -v America/Los_Angeles 33 34Historical local time information has been included here to: 35 36* provide a compendium of data about the history of civil time 37 that is useful even if the data are not 100% accurate; 38 39* give an idea of the variety of local time rules that have 40 existed in the past and thus an idea of the variety that may be 41 expected in the future; 42 43* provide a test of the generality of the local time rule description 44 system. 45 46The information in the time zone data files is by no means authoritative; 47the files currently do not even attempt to cover all time stamps before 481970, and there are undoubtedly errors even for time stamps since 1970. 49If you know that the rules are different from those in a file, by all means 50feel free to change a file (and please send the changed version to 51tz@iana.org for use in the future). Europeans take note! 52 53Thanks to these Timezone Caballeros who've made major contributions to the 54time conversion package: Keith Bostic; Bob Devine; Paul Eggert; Robert Elz; 55Guy Harris; Mark Horton; John Mackin; and Bradley White. Thanks also to 56Michael Bloom, Art Neilson, Stephen Prince, John Sovereign, and Frank Wales 57for testing work, and to Gwillim Law for checking local mean time data. 58Thanks in particular to Arthur David Olson, the project's founder and first 59maintainer, to whom the timezone community owes the greatest debt of all. 60None of them are responsible for remaining errors. 61 62Look in <ftp://ftp.iana.org/tz/releases/> for updated versions of these files. 63 64Please send comments or information to tz@iana.org. 65