1@(#)README 8.2 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 1989 update of the time zone package featured 8 9* POSIXization (including interpretation of POSIX-style TZ environment 10 variables, provided by Guy Harris), 11* ANSIfication (including versions of "mktime" and "difftime"), 12* SVIDulation (an "altzone" variable) 13* MACHination (the "gtime" function) 14* corrections to some time zone data (including corrections to the rules 15 for Great Britain and New Zealand) 16* reference data from the United States Naval Observatory for folks who 17 want to do additional time zones 18* and the 1989 data for Saudi Arabia. 19 20(Since this code will be treated as "part of the implementation" in some places 21and as "part of the application" in others, there's no good way to name 22functions, such as timegm, that are not part of the proposed ANSI C standard; 23such functions have kept their old, underscore-free names in this update.) 24 25And the "dysize" function has disappeared; it was present to allow compilation 26of the "date" command on old BSD systems, and a version of "date" is now 27provided in the package. The "date" command is not created when you "make all" 28since it may lack options provided by the version distributed with your 29operating system, or may not interact with the system in the same way the 30native version does. 31 32Since POSIX frowns on correct leap second handling, the default behavior of 33the "zic" command (in the absence of a "-L" option) has been changed to omit 34leap second information from its output files. 35 36Here is a recipe for acquiring, building, installing, and testing the 37tz distribution on a GNU/Linux or similar host. 38 39 mkdir tz 40 cd tz 41 wget 'ftp://elsie.nci.nih.gov/pub/tz*.tar.gz' 42 gzip -dc tzcode*.tar.gz | tar -xf - 43 gzip -dc tzdata*.tar.gz | tar -xf - 44 45Be sure to read the comments in "Makefile" and make any changes needed 46to make things right for your system, especially if you are using some 47platform other than GNU/Linux. Then run the following commands, 48substituting your desired installation directory for "$HOME/tzdir": 49 50 make TOPDIR=$HOME/tzdir install 51 $HOME/tzdir/etc/zdump -v America/Los_Angeles 52 53To use the new functions, use a "-ltz" option when compiling or linking. 54 55Historical local time information has been included here to: 56 57* provide a compendium of data about the history of civil time 58 that is useful even if the data are not 100% accurate; 59 60* give an idea of the variety of local time rules that have 61 existed in the past and thus an idea of the variety that may be 62 expected in the future; 63 64* provide a test of the generality of the local time rule description 65 system. 66 67The information in the time zone data files is by no means authoritative; 68the files currently do not even attempt to cover all time stamps before 691970, and there are undoubtedly errors even for time stamps since 1970. 70If you know that the rules are different from those in a file, by all means 71feel free to change file (and please send the changed version to 72tz@elsie.nci.nih.gov for use in the future). Europeans take note! 73 74Thanks to these Timezone Caballeros who've made major contributions to the 75time conversion package: Keith Bostic; Bob Devine; Paul Eggert; Robert Elz; 76Guy Harris; Mark Horton; John Mackin; and Bradley White. Thanks also to 77Michael Bloom, Art Neilson, Stephen Prince, John Sovereign, and Frank Wales 78for testing work, and to Gwillim Law for checking local mean time data. 79None of them are responsible for remaining errors. 80 81Look in the ~ftp/pub directory of elsie.nci.nih.gov 82for updated versions of these files. 83 84Please send comments or information to tz@elsie.nci.nih.gov. 85