1192890Sedwin@(#)README 8.3 2192890SedwinThis file is in the public domain, so clarified as of 3192890Sedwin2009-05-17 by Arthur David Olson. 4192890Sedwin 5192625Sedwin$FreeBSD$ 62702Swollman 72702Swollman"What time is it?" -- Richard Deacon as The King 82702Swollman"Any time you want it to be." -- Frank Baxter as The Scientist 942991Swollman (from the Bell System film "About Time") 102702Swollman 112702SwollmanThe 1989 update of the time zone package featured 122702Swollman 132702Swollman* POSIXization (including interpretation of POSIX-style TZ environment 142702Swollman variables, provided by Guy Harris), 152702Swollman* ANSIfication (including versions of "mktime" and "difftime"), 162702Swollman* SVIDulation (an "altzone" variable) 172702Swollman* MACHination (the "gtime" function) 182702Swollman* corrections to some time zone data (including corrections to the rules 192702Swollman for Great Britain and New Zealand) 202702Swollman* reference data from the United States Naval Observatory for folks who 212702Swollman want to do additional time zones 222702Swollman* and the 1989 data for Saudi Arabia. 232702Swollman 242702Swollman(Since this code will be treated as "part of the implementation" in some places 252702Swollmanand as "part of the application" in others, there's no good way to name 262702Swollmanfunctions, such as timegm, that are not part of the proposed ANSI C standard; 272702Swollmansuch functions have kept their old, underscore-free names in this update.) 282702Swollman 292702SwollmanAnd the "dysize" function has disappeared; it was present to allow compilation 302702Swollmanof the "date" command on old BSD systems, and a version of "date" is now 312702Swollmanprovided in the package. The "date" command is not created when you "make all" 322702Swollmansince it may lack options provided by the version distributed with your 332702Swollmanoperating system, or may not interact with the system in the same way the 342702Swollmannative version does. 352702Swollman 362702SwollmanSince POSIX frowns on correct leap second handling, the default behavior of 372702Swollmanthe "zic" command (in the absence of a "-L" option) has been changed to omit 382702Swollmanleap second information from its output files. 392702Swollman 40130777SstefanfHere is a recipe for acquiring, building, installing, and testing the 41130777Sstefanftz distribution on a GNU/Linux or similar host. 422702Swollman 43130777Sstefanf mkdir tz 44130777Sstefanf cd tz 45130777Sstefanf wget 'ftp://elsie.nci.nih.gov/pub/tz*.tar.gz' 46130777Sstefanf gzip -dc tzcode*.tar.gz | tar -xf - 47130777Sstefanf gzip -dc tzdata*.tar.gz | tar -xf - 48130777Sstefanf 49130777SstefanfBe sure to read the comments in "Makefile" and make any changes needed 50130777Sstefanfto make things right for your system, especially if you are using some 51130777Sstefanfplatform other than GNU/Linux. Then run the following commands, 52130777Sstefanfsubstituting your desired installation directory for "$HOME/tzdir": 53130777Sstefanf 54130777Sstefanf make TOPDIR=$HOME/tzdir install 55130777Sstefanf $HOME/tzdir/etc/zdump -v America/Los_Angeles 56130777Sstefanf 5742991SwollmanTo use the new functions, use a "-ltz" option when compiling or linking. 582702Swollman 59192625SedwinHistorical local time information has been included here to: 602702Swollman 61192625Sedwin* provide a compendium of data about the history of civil time 62192625Sedwin that is useful even if the data are not 100% accurate; 63192625Sedwin 642702Swollman* give an idea of the variety of local time rules that have 652702Swollman existed in the past and thus an idea of the variety that may be 662702Swollman expected in the future; 672702Swollman 682702Swollman* provide a test of the generality of the local time rule description 692702Swollman system. 702702Swollman 712702SwollmanThe information in the time zone data files is by no means authoritative; 72192625Sedwinthe files currently do not even attempt to cover all time stamps before 73192625Sedwin1970, and there are undoubtedly errors even for time stamps since 1970. 74192625SedwinIf you know that the rules are different from those in a file, by all means 752702Swollmanfeel free to change file (and please send the changed version to 762702Swollmantz@elsie.nci.nih.gov for use in the future). Europeans take note! 772702Swollman 782702SwollmanThanks to these Timezone Caballeros who've made major contributions to the 792702Swollmantime conversion package: Keith Bostic; Bob Devine; Paul Eggert; Robert Elz; 802702SwollmanGuy Harris; Mark Horton; John Mackin; and Bradley White. Thanks also to 812702SwollmanMichael Bloom, Art Neilson, Stephen Prince, John Sovereign, and Frank Wales 8217211Swollmanfor testing work, and to Gwillim Law for checking local mean time data. 8317211SwollmanNone of them are responsible for remaining errors. 842702Swollman 8517211SwollmanLook in the ~ftp/pub directory of elsie.nci.nih.gov 862702Swollmanfor updated versions of these files. 872702Swollman 8817211SwollmanPlease send comments or information to tz@elsie.nci.nih.gov. 89