xref: /minix3/lib/libc/time/README (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1f14fb602SLionel SambucREADME for the tz distribution
2f14fb602SLionel Sambuc
32fe8fb19SBen Gras"What time is it?" -- Richard Deacon as The King
42fe8fb19SBen Gras"Any time you want it to be." -- Frank Baxter as The Scientist
52fe8fb19SBen Gras					(from the Bell System film "About Time")
62fe8fb19SBen Gras
7*0a6a1f1dSLionel SambucThe Time Zone Database (often called tz or zoneinfo) contains code and
8*0a6a1f1dSLionel Sambucdata that represent the history of local time for many representative
9*0a6a1f1dSLionel Sambuclocations around the globe.  It is updated periodically to reflect
10*0a6a1f1dSLionel Sambucchanges made by political bodies to time zone boundaries, UTC offsets,
11*0a6a1f1dSLionel Sambucand daylight-saving rules.
122fe8fb19SBen Gras
13*0a6a1f1dSLionel SambucUnless otherwise specified, all files in the tz code and data are in
14*0a6a1f1dSLionel Sambucthe public domain, so clarified as of 2009-05-17 by Arthur David Olson.
15*0a6a1f1dSLionel SambucThe few exceptions are code derived from BSD, which uses the BSD license.
162fe8fb19SBen Gras
172fe8fb19SBen GrasHere is a recipe for acquiring, building, installing, and testing the
182fe8fb19SBen Grastz distribution on a GNU/Linux or similar host.
192fe8fb19SBen Gras
202fe8fb19SBen Gras	mkdir tz
212fe8fb19SBen Gras	cd tz
22f14fb602SLionel Sambuc	wget --retr-symlinks 'ftp://ftp.iana.org/tz/tz*-latest.tar.gz'
23f14fb602SLionel Sambuc	gzip -dc tzcode-latest.tar.gz | tar -xf -
24f14fb602SLionel Sambuc	gzip -dc tzdata-latest.tar.gz | tar -xf -
252fe8fb19SBen Gras
262fe8fb19SBen GrasBe sure to read the comments in "Makefile" and make any changes needed
272fe8fb19SBen Grasto make things right for your system, especially if you are using some
282fe8fb19SBen Grasplatform other than GNU/Linux.  Then run the following commands,
292fe8fb19SBen Grassubstituting your desired installation directory for "$HOME/tzdir":
302fe8fb19SBen Gras
312fe8fb19SBen Gras	make TOPDIR=$HOME/tzdir install
322fe8fb19SBen Gras	$HOME/tzdir/etc/zdump -v America/Los_Angeles
332fe8fb19SBen Gras
342fe8fb19SBen GrasHistorical local time information has been included here to:
352fe8fb19SBen Gras
362fe8fb19SBen Gras*	provide a compendium of data about the history of civil time
37*0a6a1f1dSLionel Sambuc	that is useful even if not 100% accurate;
382fe8fb19SBen Gras
392fe8fb19SBen Gras*	give an idea of the variety of local time rules that have
402fe8fb19SBen Gras	existed in the past and thus an idea of the variety that may be
412fe8fb19SBen Gras	expected in the future;
422fe8fb19SBen Gras
432fe8fb19SBen Gras*	provide a test of the generality of the local time rule description
442fe8fb19SBen Gras	system.
452fe8fb19SBen Gras
462fe8fb19SBen GrasThe information in the time zone data files is by no means authoritative;
47*0a6a1f1dSLionel Sambucfixes and enhancements are welcome.  Please see the file CONTRIBUTING
48*0a6a1f1dSLionel Sambucfor details.
492fe8fb19SBen Gras
50*0a6a1f1dSLionel SambucThanks to these Time Zone Caballeros who've made major contributions to the
512fe8fb19SBen Grastime conversion package: Keith Bostic; Bob Devine; Paul Eggert; Robert Elz;
522fe8fb19SBen GrasGuy Harris; Mark Horton; John Mackin; and Bradley White.  Thanks also to
532fe8fb19SBen GrasMichael Bloom, Art Neilson, Stephen Prince, John Sovereign, and Frank Wales
542fe8fb19SBen Grasfor testing work, and to Gwillim Law for checking local mean time data.
55*0a6a1f1dSLionel SambucThanks in particular to Arthur David Olson, the project's founder and first
56*0a6a1f1dSLionel Sambucmaintainer, to whom the time zone community owes the greatest debt of all.
572fe8fb19SBen GrasNone of them are responsible for remaining errors.
582fe8fb19SBen Gras
59*0a6a1f1dSLionel SambucLook in <ftp://ftp.iana.org/tz/releases/> for updated versions of these files.
602fe8fb19SBen Gras
61f14fb602SLionel SambucPlease send comments or information to tz@iana.org.
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