- tz - lists.iana.org

proposed tz followup changes for Indiana, Japan, etc.
by Paul Eggert Aug. 23, 2005

Aug. 23, 2005

> Date: Mon, 22 Aug 2005 10:49:55 -0700 > From: Eric Fischer <enf(a)pobox.com> > In the "northamerica" file, I think the > > Link America/Indianapolis EST > > line needs to be > > Link America/Indiana/Indianapolis EST Thanks for pointing out the problem, but that points out a more serious problem: starting next year, Indianapolis will observe daylight-saving time, so linking it to "EST" will no longer be appropriate. Here is a proposed patch to fix this problem, along with some other Indiana-related issues. Also, I found an article detailing Japan's daylight-saving time during the occupation, and decided that most of the country was really observing DST, so we need to update our tables. And there were a couple other minor changes in recent discussion. Changes affecting current and future time stamps. * Since Indianapolis will start observing DST next year, "Link America/Indianaopolis EST" is no longer appropriate. Link from America/Panama instead. (Thanks to Eric Fischer for pointing out the problem.) Changes affecting historical time stamps. * Japan observed DST from 1948 through 1951. I knew about this already, but did not realize how much affected daily life until I read an article in the 2005-08-10 Japan Times. (Thanks to Mayumi Negishi for writing that article.) Organizational changes * Move the following entries from "northamerica" to "backward", since they are present only for backward compatibility: EST5EDT CST6CDT MST7MDT PST8PDT EST MST HST * Sort the entries in "backward". Commentary changes * Update "Theory" to mention that uninhabited countries do not need Zone entries. (Thanks to Mark Davis for spotting this.) * Mention JDT and KDT in the commentary about abbreviations. * Mention that "US" rules are used only in the United States. (Thanks to Arthur David Olson for this.) * Update Indiana commentary to match current situation. Web page changes * Update Indiana-related commentary. Fix typo: Starke County is in Indiana, not Kentucky. * Update obsolete URL in tz-art.htm. (Thanks to Frank Vance for this.) =================================================================== RCS file: RCS/Theory,v retrieving revision 2005.12 retrieving revision 2005.12.0.1 diff -pu -r2005.12 -r2005.12.0.1 --- Theory 2005/08/22 16:06:13 2005.12 +++ Theory 2005/08/23 04:28:37 2005.12.0.1 @@ -242,6 +242,8 @@ in decreasing order of importance: Include at least one location per time zone rule set per country. One such location is enough. Use ISO 3166 (see the file iso3166.tab) to help decide whether something is a country. + However, uninhabited ISO 3166 regions like Bouvet Island + do not need locations, since local time is not defined there. If all the clocks in a country's region have agreed since 1970, don't bother to include more than one location even if subregions' clocks disagreed before 1970. =================================================================== RCS file: RCS/asia,v retrieving revision 2005.12 retrieving revision 2005.12.0.1 diff -pu -r2005.12 -r2005.12.0.1 --- asia 2005/08/22 16:05:26 2005.12 +++ asia 2005/08/23 06:14:43 2005.12.0.1 @@ -43,8 +43,8 @@ # 8:00 CST China # 9:00 CJT Central Japanese Time (1896/1937)* # 9:00 EIT east Indonesia -# 9:00 JST Japan -# 9:00 KST Korea +# 9:00 JST JDT Japan +# 9:00 KST KDT Korea # 9:30 CST (Australian) Central Standard Time # # See the `europe' file for Russia and Turkey in Asia. @@ -846,14 +846,28 @@ Zone Asia/Jerusalem 2:20:56 - LMT 1880 # Today's _Asahi Evening News_ (page 4) reports that Japan had # daylight saving between 1948 and 1951, but ``the system was discontinued # because the public believed it would lead to longer working hours.'' + +# From Mayumi Negishi in the 2005-08-10 Japan Times +# <http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nn20050810f2.htm>: +# Occupation authorities imposed daylight-saving time on Japan on +# [1948-05-01].... But lack of prior debate and the execution of +# daylight-saving time just three days after the bill was passed generated +# deep hatred of the concept.... The Diet unceremoniously passed a bill to +# dump the unpopular system in October 1951, less than a month after the San +# Francisco Peace Treaty was signed. (A government poll in 1951 showed 53% +# of the Japanese wanted to scrap daylight-saving time, as opposed to 30% who +# wanted to keep it.) + # Shanks writes that daylight saving in Japan during those years was as follows: # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -#Rule Japan 1948 only - May Sun>=1 2:00 1:00 D -#Rule Japan 1948 1951 - Sep Sat>=8 2:00 0 S -#Rule Japan 1949 only - Apr Sun>=1 2:00 1:00 D -#Rule Japan 1950 1951 - May Sun>=1 2:00 1:00 D -# but the only locations using it were US military bases. -# We go with Shanks and omit daylight saving in those years for Asia/Tokyo. +Rule Japan 1948 only - May Sun>=1 2:00 1:00 D +Rule Japan 1948 1951 - Sep Sat>=8 2:00 0 S +Rule Japan 1949 only - Apr Sun>=1 2:00 1:00 D +Rule Japan 1950 1951 - May Sun>=1 2:00 1:00 D +# but the only locations using it (for birth certificates, presumably, since +# Shanks's audience is astrologers) were US military bases. For now, assume +# that for most purposes daylight-saving time was observed; otherwise, what +# would have been the point of the 1951 poll? # From Hideyuki Suzuki (1998-11-09): # 'Tokyo' usually stands for the former location of Tokyo Astronomical @@ -883,7 +897,7 @@ Zone Asia/Jerusalem 2:20:56 - LMT 1880 Zone Asia/Tokyo 9:18:59 - LMT 1887 Dec 31 15:00u 9:00 - JST 1896 9:00 - CJT 1938 - 9:00 - JST + 9:00 Japan J%sT # Since 1938, all Japanese possessions have been like Asia/Tokyo. # Jordan =================================================================== RCS file: RCS/northamerica,v retrieving revision 2005.12 retrieving revision 2005.12.0.2 diff -pu -r2005.12 -r2005.12.0.2 --- northamerica 2005/08/22 16:05:26 2005.12 +++ northamerica 2005/08/23 06:14:43 2005.12.0.2 @@ -110,6 +110,12 @@ # # He had scored a 20-second scoop on other broadcasters. +# From Arthur David Olson (2005-08-22): +# Paul has been careful to use the "US" rules only in those locations +# that are part of the United States; this reflects the real scope of +# U.S. government action. So even though the "US" rules have changed +# in the latest release, other countries won't be affected. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule US 1918 1919 - Mar lastSun 2:00 1:00 D Rule US 1918 1919 - Oct lastSun 2:00 0 S @@ -225,8 +231,8 @@ Rule US 2007 max - Nov Sun>=1 2:00 0 S # US eastern time, represented by New York # Connecticut, Delaware, District of Columbia, most of Florida, -# Georgia, southeast Indiana (Clark, Dearborn, Floyd, Harrison, and -# Ohio counties), eastern Kentucky, Maine, Maryland, Massachusetts, +# Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky +# (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts, # New Hampshire, New Jersey, New York, North Carolina, Ohio, # Pennsylvania, Rhode Island, South Carolina, eastern Tennessee, # Vermont, Virginia, West Virginia @@ -481,27 +487,30 @@ Zone America/Boise -7:44:49 - LMT 1883 N # For a map of Indiana's time zone regions, see: # <a href="http://www.mccsc.edu/time.html"> # What time is it in Indiana? -# </a> (1999-04-06) +# </a> (2005-05-03) +# +# From Paul Eggert (2005-08-22): +# Since 1970, most of Indiana has been like America/Indiana/Indianapolis, +# with the following exceptions: +# +# - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer, +# Vandenburgh, and Warrick counties have been like America/Chicago. +# +# - Dearborn and Ohio counties have been like America/New_York. +# +# - Clark, Floyd, and Harrison counties have been like +# America/Kentucky/Louisville. +# +# - Crawford, Starke, and Switzerland counties have their own time zone +# histories as noted below. # -# From Paul Eggert (1995-12-19): -# Indiana generally observes either EST all year, or CST/CDT, -# but areas near Cincinnati and Louisville use those cities' timekeeping -# and in 1969 and 1970 the whole state observed daylight time; -# and there are other exceptions as noted below. # Shanks partitions Indiana into 345 regions, each with its own time history, # and writes ``Even newspaper reports present contradictory information.'' # Fortunately, most of the complexity occurred before our cutoff date of 1970. # -# Since 1970, EST-only Indiana has been like America/Indianapolis, -# with exceptions noted below for Crawford, Starke, and Switzerland counties. -# The parts of Indiana not listed below have been like America/Chicago, -# America/Louisville, or America/New_York. -# # Other than Indianapolis, the Indiana place names are so nondescript # that they would be ambiguous if we left them at the `America' level. # So we reluctantly put them all in a subdirectory `America/Indiana'. -# -# Most of EST-only Indiana last observed DST in 1970. # From Paul Eggert (2005-08-16): # http://www.mccsc.edu/time.html says that Indiana will use DST starting 2006, @@ -575,7 +584,7 @@ Zone America/Indiana/Vevay -5:40:16 - LM -5:00 US E%sT # Part of Kentucky left its clocks alone in 1974. -# This also includes a part of Indiana immediately adjacent to Louisville. +# This also includes Clark, Floyd, and Harrison counties in Indiana. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER Rule Louisville 1921 only - May 1 2:00 1:00 D Rule Louisville 1921 only - Sep 1 2:00 0 S @@ -716,17 +725,6 @@ Zone America/Menominee -5:50:27 - LMT 18 # _Los Angeles Times_ (1998-11-10), A1, A10; it cites # Jimmy Skaggs, _The Great Guano Rush_ (1994). -# Old names, for S5 users - -# Link LINK-FROM LINK-TO -Link America/New_York EST5EDT -Link America/Chicago CST6CDT -Link America/Denver MST7MDT -Link America/Los_Angeles PST8PDT -Link America/Indianapolis EST -Link America/Phoenix MST -Link Pacific/Honolulu HST - ################################################################################ =================================================================== RCS file: RCS/backward,v retrieving revision 2005.12 retrieving revision 2005.12.0.1 diff -pu -r2005.12 -r2005.12.0.1 --- backward 2005/08/22 16:05:26 2005.12 +++ backward 2005/08/23 04:28:37 2005.12.0.1 @@ -4,8 +4,8 @@ # and their old names. Many names changed in late 1993. Link Africa/Bamako Africa/Timbuktu -Link America/Adak America/Atka Link America/Argentina/Catamarca America/Argentina/ComodRivadavia +Link America/Adak America/Atka Link America/Argentina/Buenos_Aires America/Buenos_Aires Link America/Argentina/Catamarca America/Catamarca Link America/Argentina/Cordoba America/Cordoba @@ -23,9 +23,9 @@ Link Asia/Ashgabat Asia/Ashkhabad Link Asia/Chongqing Asia/Chungking Link Asia/Dhaka Asia/Dacca Link Asia/Macau Asia/Macao -Link Asia/Makassar Asia/Ujung_Pandang Link Asia/Jerusalem Asia/Tel_Aviv Link Asia/Thimphu Asia/Thimbu +Link Asia/Makassar Asia/Ujung_Pandang Link Asia/Ulaanbaatar Asia/Ulan_Bator Link Australia/Sydney Australia/ACT Link Australia/Sydney Australia/Canberra @@ -42,6 +42,7 @@ Link America/Rio_Branco Brazil/Acre Link America/Noronha Brazil/DeNoronha Link America/Sao_Paulo Brazil/East Link America/Manaus Brazil/West +Link America/Chicago CST6CDT Link America/Halifax Canada/Atlantic Link America/Winnipeg Canada/Central Link America/Regina Canada/East-Saskatchewan @@ -54,6 +55,8 @@ Link America/Whitehorse Canada/Yukon Link America/Santiago Chile/Continental Link Pacific/Easter Chile/EasterIsland Link America/Havana Cuba +Link America/Panama EST +Link America/New_York EST5EDT Link Africa/Cairo Egypt Link Europe/Dublin Eire Link Europe/London Europe/Belfast @@ -64,6 +67,7 @@ Link Etc/GMT GMT+0 Link Etc/GMT GMT-0 Link Etc/GMT GMT0 Link Etc/GMT Greenwich +Link Pacific/Honolulu HST Link Asia/Hong_Kong Hongkong Link Atlantic/Reykjavik Iceland Link Asia/Tehran Iran @@ -72,17 +76,20 @@ Link America/Jamaica Jamaica Link Asia/Tokyo Japan Link Pacific/Kwajalein Kwajalein Link Africa/Tripoli Libya +Link America/Phoenix MST +Link America/Denver MST7MDT Link America/Tijuana Mexico/BajaNorte Link America/Mazatlan Mexico/BajaSur Link America/Mexico_City Mexico/General -Link America/Denver Navajo Link Pacific/Auckland NZ Link Pacific/Chatham NZ-CHAT +Link America/Denver Navajo +Link Asia/Shanghai PRC +Link America/Los_Angeles PST8PDT Link Pacific/Pago_Pago Pacific/Samoa Link Pacific/Truk Pacific/Yap Link Europe/Warsaw Poland Link Europe/Lisbon Portugal -Link Asia/Shanghai PRC Link Asia/Taipei ROC Link Asia/Seoul ROK Link Asia/Singapore Singapore @@ -92,7 +99,7 @@ Link America/Anchorage US/Alaska Link America/Adak US/Aleutian Link America/Phoenix US/Arizona Link America/Chicago US/Central -Link America/Indianapolis US/East-Indiana +Link America/Indiana/Indianapolis US/East-Indiana Link America/New_York US/Eastern Link Pacific/Honolulu US/Hawaii Link America/Indiana/Knox US/Indiana-Starke =================================================================== RCS file: RCS/tz-link.htm,v retrieving revision 2005.12 retrieving revision 2005.12.0.1 diff -pu -r2005.12 -r2005.12.0.1 --- tz-link.htm 2005/08/22 16:05:26 2005.12 +++ tz-link.htm 2005/08/23 06:14:43 2005.12.0.1 @@ -62,13 +62,13 @@ Locations are identified by continent or the location, which is typically the largest city within the region. For example, <code>America/New_York</code> represents most of the <abbr title="United States">US</abbr> eastern time zone; -<code>America/Indianapolis</code> represents most of Indiana, which -uses eastern time without daylight saving time (<abbr +<code>America/Phoenix</code> represents most of Arizona, which +uses mountain time without daylight saving time (<abbr title="daylight saving time">DST</abbr>); <code>America/Detroit</code> represents most of Michigan, which uses eastern time but with different <abbr>DST</abbr> rules in 1975; and other entries represent smaller regions like Starke County, -Kentucky, which switched from central to eastern time in 1991. +Indiana, which switched from central to eastern time in 1991. To use the database on an extended <a href="http://en.wikipedia.org/wiki/POSIX"><abbr title="Portable Operating System Interface">POSIX</abbr></a> =================================================================== RCS file: RCS/tz-art.htm,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- tz-art.htm 2005/07/14 18:13:40 2005.10 +++ tz-art.htm 2005/08/23 06:14:43 2005.10.0.1 @@ -177,7 +177,7 @@ An on-line English-language translation <tr><td>Film</td><td>Bell Science - About Time</td></tr> <tr><td>Notes</td><td>The Frank Baxter/Richard Deacon extravaganza Information on ordering is available at -<a href="http://www.videoflicks.com/VF2/1035/1035893.ihtml">http://www.videoflicks.com/VF2/1035/1035893.ihtml</a></td></tr> +<a href="http://www.videoflicks.com/titles/1035/1035893.htm">http://www.videoflicks.com/titles/1035/1035893.htm</a></td></tr> </table> <hr /> <ul>

1 0

RE: How will the US daylight-saving change affect Canada, Mexico, etc.?
by Olson, Arthur David (NIH/NCI) Aug. 22, 2005

Aug. 22, 2005

It's worth noting that in the time zone data files Paul has been careful to use the "US" rules only in those locations that are part of the United States; this reflects the real scope of U. S. government action. So even though the "US" rules have changed in the latest release, other countries won't be affected. Everyone gets to be on the watch for changes in U. S. neighbors. --ado

1 0

Indiana counties start to make their time zone preferences known
by Paul Eggert Aug. 19, 2005

Aug. 19, 2005

Indiana counties wanting to change their time zones have until Sept. 16 to ask the US Dept. of Transportation to hold hearings to switch time zones. I thought I'd look to see which way their leaning. Early returns suggest a preference for Eastern time, as one might expect. None of these results are official yet, so this won't yet affect the tz data, but: Allen County residents prefer Eastern, 65%-35%. <http://www.fortwayne.com/mld/fortwayne/news/local/12413842.htm> Wabash Valley viewers prefer Eastern to Central Time, 58%-42%. <http://www.wthitv.com/newsdet.asp?id=9444> Perry County's commissioners opt for Central time, but Dubios County looks like it may stick with Eastern time. <http://www.perrycountynews.com/articles/2005/08/18/top_story/t1.txt> And, my personal favorite: Bartholomew County's commissioners have decided that it will join whatever time zone its northern neighbor Marion County chooses, regardless of public opinion. <http://www.wabashplaindealer.com/articles/2005/08/16/state_news/state3.txt>

1 0

Re: Request from CLDR committee
by Paul Eggert Aug. 18, 2005

Aug. 18, 2005

"Mark Davis" <mark.davis(a)icu-project.org> writes: > I agree that these are oddities, and that ISO really shouldn't have > had country codes for them. Unfortunately, these are more than > glitches; many systems use ISO codes internally. And completeness > helps in testing, even if these are uninhabited. It depends on what sort of "completeness" you want. To my mind, a system that can adequately represent absent or missing data is more complete than a system that cannot. > I don't see anything wrong with setting them to be the time that > would otherwise be the case, using the maritime zones. > If you don't change them, you really have to change Theory to be > accurate. It says now: > > " Include at least one location per time zone rule set per country. > One such location is enough. Use ISO 3166 (see the file > iso3166.tab) to help decide whether something is a country. > " > to something like: > > " For most countries, include at least one location per time > zone rule set per country. > One such location is enough. Use ISO 3166 (see the file > iso3166.tab) to help decide whether something is a country. > " Yes, that's true. Thanks. I'll insert the word "inhabited" before "country"; that's simpler. > The x/x/x... notation is fine for internal use, but isn't really the > best for end users. The x/x/x notation is intended only for "internal" use, if by "internal" you mean "visible to programmers and people who know how to use the shell and such-like". I don't see why end users would ever need to see it. And if end users do need to see it, I don't see why they would care whether there are slashes in it. > If we can't depend on the TZ group to assign unique final fields, we > can prepare to have deviations from them wherever > necessary. If slashes are causing problems for you, you can replace them with some other character, e.g., colons. > However, we really would like to avoid that. With all the > possible names, and with exceptions such as Bahia already in the > database, it is unclear why non-unique final fields have to be used: > perhaps you can take a few minutes to explain why that is required? It's meant as a convenience to programmers and people who know how to use the shell and such-like. It's better to use mnemonics. > I had thought that all the rules for *all* the timezones, > Etc/GMT+-X, America/Los_Angeles, etc. were defined in terms of > offsets from UTC. If some of them are not, that is very unclear from > the documentation. Can you explain which are and which aren't? They are not merely history of offsets from UTC. They also are histories of whether the time in question is daylight saving time (the tm_isdst flag of C; see <http://www.opengroup.org/onlinepubs/009695399/basedefs/time.h.html>), and the time zone abbreviation in effect (the tzname of POSIX; see <http://www.opengroup.org/onlinepubs/009695399/functions/tzname.html>). So, even if the UTC offset histories are identical, the other bits of information may mean that the Zone entries still differ. >> How about if you simplify your life by simply ignoring the Etc/* names? > > But those are used for maritime rules, right? Not in POSIX, no. You can just use something like TZ='<GMT+12>-12'. > We also need them for cases where parsing a zone gives no other > information. If we parse a string like "12:00am GMT-500", we cannot > assign it to a zone with a location, since we don't know which one > it would be. But in that case you need approximately 24*60 entries, right? That sounds excessive. >>> AQ Antarctica/Mawson >>> AQ Antarctica/Vostok -- same since 57 >> >> As far as I know it's merely a coincidence that the two bases use the >> same time zone. Most crucially the bases belong to different >> countries (so to some extent the "different country" rule applies, >> though admittedly Antarctica is special) and use different supply >> lines. I'd rather leave them alone for now. > > Then you need additional clarification in Theory, that not only do you > subtract country codes from ISO, you add them as well ;-) They do use different tz abbreviations (tzname), if that's what we need for an excuse. >>> List C. TZIDs that are linked, but refer to different locations. >> >> As a rule, these locations have identical time zone histories except >> before the advent of standard time; and LMT (by definition) is >> approximate, so I don't see the harm in keeping them linked. >> If they are trouble for your system, perhaps you can keep a >> list of exceptions and filter them out. > > We do, but that means that we have to check for "faux" links with > every version of the TZ database. If at least you put put them in a > special file that we could mechanically check for, or had some kind of > extra notation, even a comment that we could parse for (documented in > Theory), then we wouldn't have to hack around it. How about if you just ignore all the "Link" entries? Or, if that's not quite right, include the exceptional entries that need to be added.

1 0

How will the US daylight-saving change affect Canada, Mexico, etc.?
by Paul Eggert Aug. 18, 2005

Aug. 18, 2005

Several countries have used the daylight-saving rules as the United States. These include: The Bahamas (since 1976) Canada (since 1976) Cuba (this year) Haiti (this year) Mexico (since 2002) Turks and Caicos (since 1979) Now that the US is planning to change its rules, it will be interesting to see whether other countries follow suit. In some cases, the other countries have been using stable DST rules longer than the US has. Digital Home Canada reported Monday that Canadians are almost evenly split on whether to change their DST rules to match the US: 47% say yes, and 50% say no. See: Canadians Split On Shift to U.S. Daylight Saving Time (2005-08-15) http://digitalhomecanada.com/index.php?option=com_content&task=view&id=569&… New Brunswick Premier Bernard Lord said the maritime provinces of Canada may move to Eastern time. See: Canada's premiers discuss daylight saving change (2005-08-12) http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/1123856875760_13/?hub=C… My favorite take on the problem was here: Anick Jesdanun Daylight-saving switch may cause tech woes (2005-08-08) http://seattlepi.nwsource.com/business/aptech_story.asp?category=1700&slug=… Sample quote: "Adding to the complications is the fact that many computer programs now treat U.S. and Canadian time zones as the same. If Canada doesn't adopt the new dates, too, Windows, calendars and other software would have to learn additional zones." Jesdanun also has some amusing quotes on how people in Jerusalem deal with daylight-saving issues.

1 0

proposed tz changes for US, Indiana, Australia, Tunisia, Nunavut, etc.
by Paul Eggert Aug. 18, 2005

Aug. 18, 2005

Here are proposed changes to the tz database that accumulate all the changes that people have sent in recently, plus some other changes I found. I'm still having problems with tz(a)elsie.nci.nih.gov, so I'll CC: this email to Arthur David Olson, just in case. Changes affecting current and future time stamps. * The United States is extending DST starting 2007, unless it changes its mind. (Thanks to Arthur David Olson for the revised Rule lines.) * The state of Indiana is adopting DST effective 2006. * Australia will extend DST to April 2, 2006 this year only, due to the Commonwealth Games. (Thanks to David Grosz and Gwillim Law for this info.) * Tunisia is observing DST this year from May 1 00:00 to Sep 30 02:00. (Thanks to Risto Nykanen, Gwillim Law, and Oscar van Vlijmen for this info.) We don't know about next year, so for now let's assume no DST. * Kazakhstan no longer observes DST, and has merged its three time zones into two. (Thanks to Branislav Kojic and Gwillim Law for this info.) We don't know exactly when the transition occurred; for now, assume March 15. * Kyrgyzstan has abolished DST, and from now on will stay at UTC+6 (the former daylight saving time). * Nicaragua will switch back to standard time on September 18, not September 11. (This is sheer guesswork on my part.) * Southampton Island, Nunavut does not observe DST, and (as far as we know) has not observed DST since World War II. This requires a new Zone America/Coral_Harbour. (Thanks to Gwillim Law for this info.) * In Argentina, the America/Argentina/ComodRivadavia zone was wrong: Chubut actually used the same transitions as Catamarca. Fixing this removed the need for America/Argentina/ComodRivadavia (though it is retained in the "backward" file). * Change the abbreviation for East Timor Time from TPT to TLT, in response to ISO 3166's change to the abbreviation for East Timor. Changes affecting historical time stamps. * King Island, Tasmania, did not observe DST until 1971. This requires a new Zone Australia/Currie. * The transitions for Poland in 1946/1948 and 1988/1999 were a bit off. (Thanks to Przemyslaw Augustyniak for this info.) * Denmark adopted standard time on 1894-01-01, not 1894-04-01. (Thanks to Jesper Norgaard Welen for this info.) Organizational changes * Remove the following Zone entries since they are identical to other Zone entries since 1970. For backward compatibility, add links in the "backward" file so that the names still work. Africa/Timbuktu Europe/Belfast Pacific/Yap * Make America/Indiana/Indianapolis and America/Kentucky/Louisville the canonical names, with "backward" entries for America/Indianapolis and America/Louisville. * Remove an unused PRC Rule line. Commentary changes * Update "Theory" to match latest POSIX spec, to give more examples (including the planned US change), to mention plans for 64-bit time zone files, and mention the new edition of Reingold and Dershowitz. * Add commentary about the wildly conflicting info about Mongolia's time zones. * Add commentary about how Denmark adopted EU rules. (Thanks to Jesper Norgaard Welen for this info.) * Add commentary confirming Shanks over Whitman for Norway. * Add commentary about possibly-missing transitions in Nicaragua in 2000. (Thanks to Gwillim Law for this info.) Web page changes * Add references to Wikipedia for terms like "daylight saving" and "time zone". * Use Wikipedia for "POSIX" since PASC's explanation isn't as good. * Add pointers to: http://time.world-stay.com http://freshmeat.net/projects/intclock http://www.bom.gov.au/climate/averages/tables/dst_times.shtml http://met.no/met/met_lex/q_u/sommertid.html http://rom.usno.navy.mil/archives/leapsecs.html * Update some URLs that moved. * Remove pointer to Tim Berners-Lee's home page. It was a bit nosy. * Mention the new xCal draft. * Note that the HyperCard stack is no longer maintained. =================================================================== RCS file: RCS/Theory,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- Theory 2005/07/14 18:13:38 2005.10 +++ Theory 2005/08/18 05:36:46 2005.10.0.1 @@ -12,26 +12,27 @@ ----- Time and date functions ----- -These time and date functions are upwards compatible with POSIX.1, +These time and date functions are upwards compatible with POSIX, an international standard for UNIX-like systems. -As of this writing, the current edition of POSIX.1 is: +As of this writing, the current edition of POSIX is: - Information technology --Portable Operating System Interface (POSIX (R)) - -- Part 1: System Application Program Interface (API) [C Language] - ISO/IEC 9945-1:1996 - ANSI/IEEE Std 1003.1, 1996 Edition - 1996-07-12 + Standard for Information technology + -- Portable Operating System Interface (POSIX (R)) + -- System Interfaces + IEEE Std 1003.1, 2004 Edition + <http://www.opengroup.org/online-pubs?DOC=7999959899> + <http://www.opengroup.org/pubs/catalog/t041.htm> -POSIX.1 has the following properties and limitations. +POSIX has the following properties and limitations. -* In POSIX.1, time display in a process is controlled by the - environment variable TZ. Unfortunately, the POSIX.1 TZ string takes +* In POSIX, time display in a process is controlled by the + environment variable TZ. Unfortunately, the POSIX TZ string takes a form that is hard to describe and is error-prone in practice. - Also, POSIX.1 TZ strings can't deal with other (for example, Israeli) + Also, POSIX TZ strings can't deal with other (for example, Israeli) daylight saving time rules, or situations where more than two time zone abbreviations are used in an area. - The POSIX.1 TZ string takes the following form: + The POSIX TZ string takes the following form: stdoffset[dst[offset],date[/time],date[/time]] @@ -40,6 +41,9 @@ POSIX.1 has the following properties and std and dst are 3 or more characters specifying the standard and daylight saving time (DST) zone names. + Starting with POSIX.1-2001, std and dst may also be + in a quoted form like "<UTC+10>"; this allows + "+" and "-" in the names. offset is of the form `[-]hh:[mm[:ss]]' and specifies the offset west of UTC. The default DST offset is one hour @@ -61,15 +65,26 @@ POSIX.1 has the following properties and where week 1 is the first week in which day d appears, and `5' stands for the last week in which day d appears (which may be either the 4th or 5th week). + + Here is an example POSIX TZ string, for US Pacific time using rules + appropriate from 1987 through 2006: -* In POSIX.1, when a TZ value like "EST5EDT" is parsed, - typically the current US DST rules are used, + TZ='PST8PDT,M4.1.0/02:00,M10.5.0/02:00' + + This POSIX TZ string is hard to remember, and mishandles time stamps + before 1987 and after 2006. With this package you can use this + instead: + + TZ='America/Los_Angeles' + +* POSIX does not define the exact meaning of TZ values like "EST5EDT". + Typically the current US DST rules are used to interpret such values, but this means that the US DST rules are compiled into each program that does time conversion. This means that when US time conversion rules change (as in the United States in 1987), all programs that do time conversion must be recompiled to ensure proper results. -* In POSIX.1, there's no tamper-proof way for a process to learn the +* In POSIX, there's no tamper-proof way for a process to learn the system's best idea of local wall clock. (This is important for applications that an administrator wants used only at certain times-- without regard to whether the user has fiddled the "TZ" environment @@ -78,9 +93,9 @@ POSIX.1 has the following properties and daylight saving time shifts--as might be required to limit phone calls to off-peak hours.) -* POSIX.1 requires that systems ignore leap seconds. +* POSIX requires that systems ignore leap seconds. -These are the extensions that have been made to the POSIX.1 functions: +These are the extensions that have been made to the POSIX functions: * The "TZ" environment variable is used in generating the name of a file from which time zone information is read (or is interpreted a la @@ -108,7 +123,7 @@ These are the extensions that have been * To handle places where more than two time zone abbreviations are used, the functions "localtime" and "gmtime" set tzname[tmp->tm_isdst] (where "tmp" is the value the function returns) to the time zone - abbreviation to be used. This differs from POSIX.1, where the elements + abbreviation to be used. This differs from POSIX, where the elements of tzname are only changed as a result of calls to tzset. * Since the "TZ" environment variable can now be used to control time @@ -135,6 +150,19 @@ These are the extensions that have been Points of interest to folks with other systems: +* In the near future this package is intended to generate time zone + information files containing two sets of data. The first set + uses 32-bit time stamps covering times from 1901-12-13 + 20:45:52 through 2038-01-19 03:14:07 UTC; it is for backward + compatibility with older versions of this and other libraries. + The second set uses 64-bit time stamps containing about 400 + years of transition times, which are extrapolated into the + indefinite future; it is for newer libraries, typically on + hosts with 64-bit time stamps. New files are approximately + nine times the size of the old, because the added data set + contains about four times as many transitions, and its time + stamps are twice as wide. + * This package is already part of many POSIX-compliant hosts, including BSD, HP, Linux, Network Appliance, SCO, SGI, and Sun. On such hosts, the primary use of this package @@ -172,9 +200,9 @@ Hewlett Packard, offer a wider selection beyond those provided here. The absence of such functions from this package is not meant to discourage the development, standardization, or use of such functions. Rather, their absence reflects the decision to make this package -contain valid extensions to POSIX.1, to ensure its broad -acceptability. If more powerful time conversion functions can be standardized, -so much the better. +contain valid extensions to POSIX, to ensure its broad acceptability. If +more powerful time conversion functions can be standardized, so much the +better. ----- Names of time zone rule files ----- @@ -262,7 +290,8 @@ in decreasing order of importance: If a name is changed, put its old spelling in the `backward' file. The file `zone.tab' lists the geographical locations used to name -time zone rule files. +time zone rule files. It is intended to be an exhaustive list +of canonical names for geographic regions. Older versions of this package used a different naming scheme, and these older names are still supported. @@ -276,7 +305,7 @@ and `Factory' (see the file `factory'). ----- Time zone abbreviations ----- When this package is installed, it generates time zone abbreviations -like `EST' to be compatible with human tradition and POSIX.1. +like `EST' to be compatible with human tradition and POSIX. Here are the general rules used for choosing time zone abbreviations, in decreasing order of importance: @@ -291,17 +320,16 @@ in decreasing order of importance: preferred "ChST", so the rule has been relaxed. This rule guarantees that all abbreviations could have - been specified by a POSIX.1 TZ string. POSIX.1 + been specified by a POSIX TZ string. POSIX requires at least three characters for an - abbreviation. POSIX.1-1996 says that an abbreviation + abbreviation. POSIX through 2000 says that an abbreviation cannot start with ':', and cannot contain ',', '-', - '+', NUL, or a digit. Draft 7 of POSIX 1003.1-200x - changes this rule to say that an abbreviation can - contain only '-', '+', and alphanumeric characters in - the current locale. To be portable to both sets of + '+', NUL, or a digit. POSIX from 2001 on changes this + rule to say that an abbreviation can contain only '-', '+', + and alphanumeric characters from the portable character set + in the current locale. To be portable to both sets of rules, an abbreviation must therefore use only ASCII - letters, as these are the only letters that are - alphabetic in all locales. + letters. Use abbreviations that are in common use among English-speakers, e.g. `EST' for Eastern Standard Time in North America. @@ -327,8 +355,9 @@ in decreasing order of importance: and then append `T', `ST', etc. as before; e.g. `VLAST' for VLAdivostok Summer Time. - Use "zzz" for locations while uninhabited. The mnemonic is that - these locations are, in some sense, asleep. + Use UTC (with time zone abbreviation "zzz") for locations while + uninhabited. The "zzz" mnemonic is that these locations are, + in some sense, asleep. Application writers should note that these abbreviations are ambiguous in practice: e.g. `EST' has a different meaning in Australia than @@ -342,10 +371,10 @@ abbreviations like `EST'; this avoids th Calendrical issues are a bit out of scope for a time zone database, but they indicate the sort of problems that we would run into if we extended the time zone database further into the past. An excellent -resource in this area is Nachum Dershowitz and Edward M. Reingold, -<a href="http://emr.cs.uiuc.edu/home/reingold/calendar-book/index.shtml"> -Calendrical Calculations -</a>, Cambridge University Press (1997). Other information and +resource in this area is Edward M. Reingold and Nachum Dershowitz, +<a href="http://emr.cs.uiuc.edu/home/reingold/calendar-book/second-edition/"> +Calendrical Calculations: The Millennium Edition +</a>, Cambridge University Press (2001). Other information and sources are given below. They sometimes disagree. @@ -545,7 +574,7 @@ Sources: Michael Allison and Robert Schmunk, "Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock" -<http://www.giss.nasa.gov/tools/mars24/help/notes.html> (2004-03-15). +<http://www.giss.nasa.gov/tools/mars24/help/notes.html> (2004-07-30). Jia-Rui Chong, "Workdays Fit for a Martian", Los Angeles Times (2004-01-14), pp A1, A20-A21. =================================================================== RCS file: RCS/africa,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- africa 2005/07/14 18:13:38 2005.10 +++ africa 2005/08/18 05:36:46 2005.10.0.1 @@ -348,9 +348,6 @@ Zone Africa/Bamako -0:32:00 - LMT 1912 0:00 - GMT 1934 Feb 26 -1:00 - WAT 1960 Jun 20 0:00 - GMT -# no longer different from Bamako, but too famous to omit -Zone Africa/Timbuktu -0:12:04 - LMT 1912 - 0:00 - GMT # Mauritania # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -557,6 +554,23 @@ Zone Africa/Lome 0:04:52 - LMT 1893 0:00 - GMT # Tunisia + +# From Gwillim Law (2005-04-30): +# +# My correspondent, Risto Nykanen, has alerted me to another adoption of DST, +# this time in Tunisia. According to Yahoo France News +# <http://fr.news.yahoo.com/050426/5/4dumk.html>, in a story attributed to AP +# and dated 2005-04-26, "Tunisia has decided to advance its official time by +# one hour, starting on Sunday, May 1. Henceforth, Tunisian time will be +# UTC+2 instead of UTC+1. The change will take place at 23:00 UTC next +# Saturday." (My translation) +# +# From Oscar van Vlijmen (2005-05-02): +# LaPresse, the first national daily newspaper ... +# <http://www.lapresse.tn/archives/archives280405/actualites/lheure.html> +# ... DST for 2005: on: Sun May 1 0h standard time, off: Fri Sept. 30, +# 1h standard time. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Tunisia 1939 only - Apr 15 23:00s 1:00 S Rule Tunisia 1939 only - Nov 18 23:00s 0 - @@ -579,6 +593,8 @@ Rule Tunisia 1988 only - Jun 1 0:00s 1 Rule Tunisia 1988 1990 - Sep lastSun 0:00s 0 - Rule Tunisia 1989 only - Mar 26 0:00s 1:00 S Rule Tunisia 1990 only - May 1 0:00s 1:00 S +Rule Tunisia 2005 only - May 1 0:00s 1:00 S +Rule Tunisia 2005 only - Sep 30 1:00s 0 - # Shanks gives 0:09 for Paris Mean Time; go with Howse's more precise 0:09:21. # Shanks says the 1911 switch occurred on Mar 9; go with Howse's Mar 11. # Zone NAME GMTOFF RULES FORMAT [UNTIL] =================================================================== RCS file: RCS/asia,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- asia 2005/07/14 18:13:38 2005.10 +++ asia 2005/08/18 05:36:46 2005.10.0.1 @@ -201,7 +201,6 @@ Zone Asia/Phnom_Penh 6:59:40 - LMT 1906 Rule Shang 1940 only - Jun 3 0:00 1:00 D Rule Shang 1940 1941 - Oct 1 0:00 0 S Rule Shang 1941 only - Mar 16 0:00 1:00 D -Rule PRC 1949 only - Jan 1 0:00 0 S Rule PRC 1986 only - May 4 0:00 1:00 D Rule PRC 1986 1991 - Sep Sun>=11 0:00 0 S Rule PRC 1987 1991 - Apr Sun>=10 0:00 1:00 D @@ -387,11 +386,11 @@ Zone Asia/Tbilisi 2:59:16 - LMT 1880 # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Dili 8:22:20 - LMT 1912 - 8:00 - TPT 1942 Feb 21 23:00 # E Timor Time + 8:00 - TLT 1942 Feb 21 23:00 # E Timor Time 9:00 - JST 1945 Aug - 9:00 - TPT 1976 May 3 + 9:00 - TLT 1976 May 3 8:00 - CIT 2000 Sep 17 00:00 - 9:00 - TPT + 9:00 - TLT # India # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -930,14 +929,16 @@ Rule Jordan 2000 max - Mar lastThu 0:00s Zone Asia/Amman 2:23:44 - LMT 1931 2:00 Jordan EE%sT + # Kazakhstan + # From Paul Eggert (1996-11-22): # Andrew Evtichov (1996-04-13) writes that Kazakhstan # stayed in sync with Moscow after 1990, and that Aqtobe (formerly Aktyubinsk) # and Aqtau (formerly Shevchenko) are the largest cities in their zones. # Guess that Aqtau and Aqtobe diverged in 1995, since that's the first time # IATA SSIM mentions a third time zone in Kazakhstan. -# + # From Paul Eggert (2001-10-18): # German Iofis, ELSI, Almaty (2001-10-09) reports that Kazakhstan uses # RussiaAsia rules, instead of switching at 00:00 as the IATA has it. @@ -947,7 +948,7 @@ Zone Asia/Amman 2:23:44 - LMT 1931 # - Kazakhstan did not observe DST in 1991. # - Qyzylorda switched from +5:00 to +6:00 on 1992-01-19 02:00. # - Oral switched from +5:00 to +4:00 in spring 1989. -# + # <a href="http://www.kazsociety.org.uk/news/2005/03/30.htm"> # From Kazakhstan Embassy's News Bulletin #11 (2005-03-21): # </a> @@ -955,6 +956,16 @@ Zone Asia/Amman 2:23:44 - LMT 1931 # daylight saving time citing lack of economic benefits and health # complications coupled with a decrease in productivity. # +# From Branislav Kojic (in Astana) via Gwillim Law (2005-06-28): +# ... what happened was that the former Kazakhstan Eastern time zone +# was "blended" with the Central zone. Therefore, Kazakhstan now has +# two time zones, and difference between them is one hour. The zone +# closer to UTC is the former Western zone (probably still called the +# same), encompassing four provinces in the west: Aqtobe, Atyrau, +# Mangghystau, and West Kazakhstan. The other zone encompasses +# everything else.... I guess that would make Kazakhstan time zones +# de jure UTC+5 and UTC+6 respectively. + # # Zone NAME GMTOFF RULES FORMAT [UNTIL] # @@ -998,7 +1009,7 @@ Zone Asia/Aqtau 3:21:04 - LMT 1924 May 5:00 - SHET 1991 Dec 16 # independence 5:00 RussiaAsia AQT%sT 1995 Mar lastSun 2:00 # Aqtau Time 4:00 RussiaAsia AQT%sT 2005 Mar 15 - 4:00 - AQTT + 5:00 - AQTT # West Kazakhstan Zone Asia/Oral 3:25:24 - LMT 1924 May 2 # or Ural'sk 4:00 - URAT 1930 Jun 21 # Ural'sk time @@ -1009,10 +1020,17 @@ Zone Asia/Oral 3:25:24 - LMT 1924 May 2 4:00 RussiaAsia URA%sT 1991 4:00 - URAT 1991 Dec 16 # independence 4:00 RussiaAsia ORA%sT 2005 Mar 15 # Oral Time - 4:00 - ORAT + 5:00 - ORAT # Kyrgyzstan (Kirgizstan) # Transitions through 1991 are from Shanks. + +# From Paul Eggert (2005-08-15): +# According to an article dated today in the Kyrgyzstan Development Gateway +# <http://eng.gateway.kg/cgi-bin/page.pl?id=1&story_name=doc9979.shtml> +# Kyrgyzstan is canceling the daylight saving time system. I take the article +# to mean that they will leave their clocks at 6 hours ahead of UTC. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Kirgiz 1992 1996 - Apr Sun>=7 0:00s 1:00 S Rule Kirgiz 1992 1996 - Sep lastSun 0:00 0 - @@ -1191,6 +1209,24 @@ Zone Indian/Maldives 4:54:00 - LMT 1880 # For now, assume Rives McDow's informant got confused about Friday vs # Saturday, and that his 2001 dates should have 1 added to them. +# From Paul Eggert (2005-07-26): +# We have wildly conflicting information about Mongolia's time zones. +# Bill Bonnet (2005-05-19) reports that the US Embassy in Ulaanbaatar says +# there is only one time zone and that DST is observed, citing Microsoft +# Windows XP as the source. Risto Nykanen (2005-05-16) reports that +# travelmongolia.org says there are two time zones (UTC+7, UTC+8) with no DST. +# Oscar van Vlijmen (2005-05-20) reports that the Mongolian Embassy in +# Washington, DC says there are two time zones, with DST observed. +# He also found +# <http://ubpost.mongolnews.mn/index.php?subaction=showcomments&id=1111634894&…> +# which also says that there is DST, and which has a comment by "Toddius" +# (2005-03-31 06:05 +0700) saying "Mongolia actually has 3.5 time zones. +# The West (OLGII) is +7 GMT, most of the country is ULAT is +8 GMT +# and some Eastern provinces are +9 GMT but Sukhbaatar Aimag is SUHK +8.5 GMT. +# The SUKH timezone is new this year, it is one of the few things the +# parliament passed during the tumultuous winter session." +# For now, let's ignore this information, until we have more confirmation. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Mongol 1983 1984 - Apr 1 0:00 1:00 S Rule Mongol 1983 only - Oct 1 0:00 0 - =================================================================== RCS file: RCS/australasia,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- australasia 2005/07/14 18:13:38 2005.10 +++ australasia 2005/08/18 05:36:46 2005.10.0.1 @@ -77,7 +77,9 @@ Rule AS 1991 only - Mar Sun>=1 2:00s 0 - Rule AS 1992 only - Mar Sun>=18 2:00s 0 - Rule AS 1993 only - Mar Sun>=1 2:00s 0 - Rule AS 1994 only - Mar Sun>=18 2:00s 0 - -Rule AS 1995 max - Mar lastSun 2:00s 0 - +Rule AS 1995 2005 - Mar lastSun 2:00s 0 - +Rule AS 2006 only - Apr Sun>=1 2:00s 0 - +Rule AS 2007 max - Mar lastSun 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Australia/Adelaide 9:14:20 - LMT 1895 Feb 9:00 - CST 1899 May @@ -85,6 +87,11 @@ Zone Australia/Adelaide 9:14:20 - LMT 18 9:30 AS CST # Tasmania +# +# From Paul Eggert (2005-08-16): +# <http://www.bom.gov.au/climate/averages/tables/dst_times.shtml> +# says King Island didn't observe DST from WWII until late 1971. +# # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule AT 1967 only - Oct Sun>=1 2:00s 1:00 - Rule AT 1968 only - Mar lastSun 2:00s 0 - @@ -99,15 +106,22 @@ Rule AT 1987 1990 - Mar Sun>=15 2:00s 0 Rule AT 1987 only - Oct Sun>=22 2:00s 1:00 - Rule AT 1988 1990 - Oct lastSun 2:00s 1:00 - Rule AT 1991 1999 - Oct Sun>=1 2:00s 1:00 - -Rule AT 1991 max - Mar lastSun 2:00s 0 - +Rule AT 1991 2005 - Mar lastSun 2:00s 0 - Rule AT 2000 only - Aug lastSun 2:00s 1:00 - Rule AT 2001 max - Oct Sun>=1 2:00s 1:00 - +Rule AT 2006 only - Apr Sun>=1 2:00s 0 - +Rule AT 2007 max - Mar lastSun 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Australia/Hobart 9:49:16 - LMT 1895 Sep 10:00 - EST 1916 Oct 1 2:00 10:00 1:00 EST 1917 Feb 10:00 Aus EST 1967 10:00 AT EST +Zone Australia/Currie 9:35:28 - LMT 1895 Sep + 10:00 - EST 1916 Oct 1 2:00 + 10:00 1:00 EST 1917 Feb + 10:00 Aus EST 1971 Jul + 10:00 AT EST # Victoria # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S @@ -118,9 +132,11 @@ Rule AV 1986 1990 - Mar Sun>=15 2:00s 0 Rule AV 1986 1987 - Oct Sun>=15 2:00s 1:00 - Rule AV 1988 1999 - Oct lastSun 2:00s 1:00 - Rule AV 1991 1994 - Mar Sun>=1 2:00s 0 - -Rule AV 1995 max - Mar lastSun 2:00s 0 - +Rule AV 1995 2005 - Mar lastSun 2:00s 0 - Rule AV 2000 only - Aug lastSun 2:00s 1:00 - Rule AV 2001 max - Oct lastSun 2:00s 1:00 - +Rule AV 2006 only - Apr Sun>=1 2:00s 0 - +Rule AV 2007 max - Mar lastSun 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Australia/Melbourne 9:39:52 - LMT 1895 Feb 10:00 Aus EST 1971 @@ -137,9 +153,11 @@ Rule AN 1986 1989 - Mar Sun>=15 2:00s 0 Rule AN 1986 only - Oct 19 2:00s 1:00 - Rule AN 1987 1999 - Oct lastSun 2:00s 1:00 - Rule AN 1990 1995 - Mar Sun>=1 2:00s 0 - -Rule AN 1996 max - Mar lastSun 2:00s 0 - +Rule AN 1996 2005 - Mar lastSun 2:00s 0 - Rule AN 2000 only - Aug lastSun 2:00s 1:00 - Rule AN 2001 max - Oct lastSun 2:00s 1:00 - +Rule AN 2006 only - Apr Sun>=1 2:00s 0 - +Rule AN 2007 max - Mar lastSun 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Australia/Sydney 10:04:52 - LMT 1895 Feb 10:00 Aus EST 1971 @@ -160,9 +178,11 @@ Rule LH 1986 1989 - Mar Sun>=15 2:00 0 - Rule LH 1986 only - Oct 19 2:00 0:30 - Rule LH 1987 1999 - Oct lastSun 2:00 0:30 - Rule LH 1990 1995 - Mar Sun>=1 2:00 0 - -Rule LH 1996 max - Mar lastSun 2:00 0 - +Rule LH 1996 2005 - Mar lastSun 2:00 0 - Rule LH 2000 only - Aug lastSun 2:00 0:30 - Rule LH 2001 max - Oct lastSun 2:00 0:30 - +Rule LH 2006 only - Apr Sun>=1 2:00 0 - +Rule LH 2007 max - Mar lastSun 2:00 0 - Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb 10:00 - EST 1981 Mar 10:30 LH LHST @@ -264,9 +284,6 @@ Zone Pacific/Kwajalein 11:09:20 - LMT 19 # Micronesia # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Pacific/Yap 9:12:32 - LMT 1901 # Colonia - 9:00 - YAPT 1969 Oct # Yap Time - 10:00 - YAPT Zone Pacific/Truk 10:07:08 - LMT 1901 10:00 - TRUT # Truk Time Zone Pacific/Ponape 10:32:52 - LMT 1901 # Kolonia @@ -670,6 +687,24 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # Standard Time Act, 1898 # </a> +# From David Grosz (2005-06-13): +# It was announced last week that Daylight Saving would be extended by +# one week next year to allow for the 2006 Commonwealth Games. +# Daylight Saving is now to end for next year only on the first Sunday +# in April instead of the last Sunday in March. +# +# From Gwillim Law (2005-06-14): +# I did some Googling and found that all of those states (and territory) plan +# to extend DST together in 2006. +# ACT: http://www.cmd.act.gov.au/mediareleases/fileread.cfm?file=86.txt +# New South Wales: http://www.thecouriermail.news.com.au/common/story_page/0,5936,15538869%255… +# South Australia: http://www.news.com.au/story/0,10117,15555031-1246,00.html +# Tasmania: http://www.media.tas.gov.au/release.php?id=14772 +# Victoria: I wasn't able to find anything separate, but the other articles +# allude to it. +# But not Queensland +# http://www.news.com.au/story/0,10117,15564030-1248,00.html. + # Northern Territory # From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06): @@ -856,7 +891,7 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # 1994 was at +0930 as John Connolly's customer seems to assert, then I can # only conclude that the actual rule is more complicated.... -# From John Warburton <jwarb(a)SACBH.com.au> (1994-10-07): +# From John Warburton (1994-10-07): # The new Daylight Savings dates for South Australia ... # was gazetted in the Government Hansard on Sep 26 1994.... # start on last Sunday in October and end in last sunday in March. =================================================================== RCS file: RCS/backward,v retrieving revision 2005.3 retrieving revision 2005.3.0.1 diff -pu -r2005.3 -r2005.3.0.1 --- backward 2005/01/17 23:36:17 2005.3 +++ backward 2005/08/18 05:36:46 2005.3.0.1 @@ -3,14 +3,18 @@ # This file provides links between current names for time zones # and their old names. Many names changed in late 1993. +Link Africa/Bamako Africa/Timbuktu Link America/Adak America/Atka +Link America/Argentina/Catamarca America/Argentina/ComodRivadavia Link America/Argentina/Buenos_Aires America/Buenos_Aires Link America/Argentina/Catamarca America/Catamarca Link America/Argentina/Cordoba America/Cordoba Link America/Tijuana America/Ensenada -Link America/Indianapolis America/Fort_Wayne +Link America/Indiana/Indianapolis America/Fort_Wayne +Link America/Indiana/Indianapolis America/Indianapolis Link America/Argentina/Jujuy America/Jujuy Link America/Indiana/Knox America/Knox_IN +Link America/Kentucky/Louisville America/Louisville Link America/Argentina/Mendoza America/Mendoza Link America/Rio_Branco America/Porto_Acre Link America/Argentina/Cordoba America/Rosario @@ -52,6 +56,7 @@ Link Pacific/Easter Chile/EasterIsland Link America/Havana Cuba Link Africa/Cairo Egypt Link Europe/Dublin Eire +Link Europe/London Europe/Belfast Link Europe/Chisinau Europe/Tiraspol Link Europe/London GB Link Europe/London GB-Eire @@ -74,6 +79,7 @@ Link America/Denver Navajo Link Pacific/Auckland NZ Link Pacific/Chatham NZ-CHAT Link Pacific/Pago_Pago Pacific/Samoa +Link Pacific/Truk Pacific/Yap Link Europe/Warsaw Poland Link Europe/Lisbon Portugal Link Asia/Shanghai PRC =================================================================== RCS file: RCS/europe,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- europe 2005/07/14 18:13:38 2005.10 +++ europe 2005/08/18 05:36:46 2005.10.0.1 @@ -422,13 +422,6 @@ Zone Europe/London -0:01:15 - LMT 1847 D 1:00 - BST 1971 Oct 31 2:00u 0:00 GB-Eire %s 1996 0:00 EU GMT/BST -Zone Europe/Belfast -0:23:40 - LMT 1880 Aug 2 - -0:25:21 - DMT 1916 May 21 2:00 # Dublin/Dunsink MT - -0:25:21 1:00 IST 1916 Oct 1 2:00s # Irish Summer Time - 0:00 GB-Eire %s 1968 Oct 27 - 1:00 - BST 1971 Oct 31 2:00u - 0:00 GB-Eire %s 1996 - 0:00 EU GMT/BST Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2 -0:25:21 - DMT 1916 May 21 2:00 -0:25:21 1:00 IST 1916 Oct 1 2:00s @@ -756,6 +749,40 @@ Zone Europe/Prague 0:57:44 - LMT 1850 1:00 EU CE%sT # Denmark, Faeroe Islands, and Greenland + +# From Jesper Norgaard Welen (2005-04-26): +# http://www.hum.aau.dk/~poe/tid/tine/DanskTid.htm says that the law +# [introducing standard time] was in effect from 1894-01-01.... +# The page http://www.retsinfo.dk/_GETDOCI_/ACCN/A18930008330-REGL +# confirms this, and states that the law was put forth 1893-03-29. +# +# The EU treaty with effect from 1973: +# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19722110030-REGL +# +# This provoked a new law from 1974 to make possible summer time changes +# in subsequenet decrees with the law +# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19740022330-REGL +# +# It seems however that no decree was set forward until 1980. I have +# not found any decree, but in another related law, the effecting DST +# changes are stated explicitly to be from 1980-04-06 at 02:00 to +# 1980-09-28 at 02:00. If this is true, this differs slightly from +# the EU rule in that DST runs to 02:00, not 03:00. We don't know +# when Denmark began using the EU rule correctly, but we have only +# confirmation of the 1980-time, so I presume it was correct in 1981: +# The law is about the management of the extra hour, concerning +# working hours reported and effect on obligatory-rest rules (which +# was suspended on that night): +# http://www.retsinfo.dk/_GETDOCI_/ACCN/C19801120554-REGL + +# From Jesper Norgaard Welen (2005-06-11): +# The Herning Folkeblad (1980-09-26) reported that the night between +# Saturday and Sunday the clock is set back from three to two. + +# From Paul Eggert (2005-06-11): +# Hence the "02:00" of the 1980 law refers to standard time, not +# wall-clock time, and so the EU rules were in effect in 1980. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Denmark 1916 only - May 14 23:00 1:00 S Rule Denmark 1916 only - Sep 30 23:00 0 - @@ -768,13 +795,10 @@ Rule Denmark 1947 only - May 4 2:00s 1 Rule Denmark 1947 only - Aug 10 2:00s 0 - Rule Denmark 1948 only - May 9 2:00s 1:00 S Rule Denmark 1948 only - Aug 8 2:00s 0 - -# Whitman also gives 1949 Apr 9 to 1949 Oct 1, and disagrees in minor ways -# about many of the above dates; go with Shanks. # -# For 1894, Shanks says Jan, Whitman Apr; go with Whitman. # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Copenhagen 0:50:20 - LMT 1890 - 0:50:20 - CMT 1894 Apr # Copenhagen Mean Time + 0:50:20 - CMT 1894 Jan 1 # Copenhagen MT 1:00 Denmark CE%sT 1942 Nov 2 2:00s 1:00 C-Eur CE%sT 1945 Apr 2 2:00 1:00 Denmark CE%sT 1980 @@ -1608,12 +1632,10 @@ Zone Europe/Amsterdam 0:19:32 - LMT 1835 1:00 EU CE%sT # Norway +# http://met.no/met/met_lex/q_u/sommertid.html (2004-01) agrees with Shanks. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -# Whitman gives 1916 May 21 - 1916 Oct 21; go with Shanks. Rule Norway 1916 only - May 22 1:00 1:00 S Rule Norway 1916 only - Sep 30 0:00 0 - -# Whitman says DST observed 1935-08-11/1942-11-01, then 1943-03-29/10-04, -# 1944-04-03/10-02, and 1945-04-01/10-01; go with Shanks. Rule Norway 1945 only - Apr 2 2:00s 1:00 S Rule Norway 1945 only - Oct 1 2:00s 0 - Rule Norway 1959 1964 - Mar Sun>=15 2:00s 1:00 S @@ -1686,19 +1708,26 @@ Rule Poland 1944 only - Oct 4 2:00 0 - # For 1944-1948 Whitman gives the previous day; go with Shanks. Rule Poland 1945 only - Apr 29 0:00 1:00 S Rule Poland 1945 only - Nov 1 0:00 0 - -Rule Poland 1946 only - Apr 14 0:00 1:00 S -Rule Poland 1946 only - Sep 7 0:00 0 - -Rule Poland 1947 only - May 4 0:00 1:00 S -Rule Poland 1947 1948 - Oct Sun>=1 0:00 0 - -Rule Poland 1948 only - Apr 18 0:00 1:00 S -# Whitman also gives 1949 Apr 9 - 1949 Oct 1; go with Shanks. +# For 1946 on the source is Kazimierz Borkowski, +# Torun Center for Astronomy, Dept. of Radio Astronomy, Nicolaus Copernicus U., +# <http://www.astro.uni.torun.pl/~kb/Artykuly/U-PA/Czas2.htm#tth_tAb1> +# Thanks to Przemyslaw Augustyniak (2005-05-28) for this reference. +# He also gives these further references: +# Mon Pol nr 13, poz 162 (1995) <http://www.abc.com.pl/serwis/mp/1995/0162.htm> +# Druk nr 2180 (2003) <http://www.senat.gov.pl/k5/dok/sejm/053/2180.pdf> +Rule Poland 1946 only - Apr 14 0:00s 1:00 S +Rule Poland 1946 only - Oct 7 2:00s 0 - +Rule Poland 1947 only - May 4 2:00s 1:00 S +Rule Poland 1947 1949 - Oct Sun>=1 2:00s 0 - +Rule Poland 1948 only - Apr 18 2:00s 1:00 S +Rule Poland 1949 only - Apr 10 2:00s 1:00 S Rule Poland 1957 only - Jun 2 1:00s 1:00 S Rule Poland 1957 1958 - Sep lastSun 1:00s 0 - Rule Poland 1958 only - Mar 30 1:00s 1:00 S Rule Poland 1959 only - May 31 1:00s 1:00 S Rule Poland 1959 1961 - Oct Sun>=1 1:00s 0 - Rule Poland 1960 only - Apr 3 1:00s 1:00 S -Rule Poland 1961 1964 - May Sun>=25 1:00s 1:00 S +Rule Poland 1961 1964 - May lastSun 1:00s 1:00 S Rule Poland 1962 1964 - Sep lastSun 1:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Warsaw 1:24:00 - LMT 1880 @@ -1707,24 +1736,8 @@ Zone Europe/Warsaw 1:24:00 - LMT 1880 2:00 Poland EE%sT 1922 Jun 1:00 Poland CE%sT 1940 Jun 23 2:00 1:00 C-Eur CE%sT 1944 Oct - 1:00 Poland CE%sT 1977 Apr 3 1:00 - 1:00 W-Eur CE%sT 1999 -# IATA SSIM (1991/1996) gives EU rules, but the _The Warsaw Voice_ -# <a href="http://www.warsawvoice.com.pl/v361/NewsInBrief.shtml"> -# http://www.warsawvoice.com/pl/v361/NewsInBrief.shtml (1995-09-24) -# </a> -# says the autumn 1995 switch was at 02:00. -# Stick with W-Eur for now. -# -# From Marcin Kasperski (1999-06-10): -# According to my colleagues someone recently decided, that Poland would -# follow European Union regulations, so - I think - the matter is not -# worth further discussion. -# -# From Paul Eggert (1999-06-10): -# Kasperski also writes that the government futzed with the rules in 1997 -# or 1998 but he doesn't remember the details. Assume they switched to -# EU rules in 1999. + 1:00 Poland CE%sT 1977 + 1:00 W-Eur CE%sT 1988 1:00 EU CE%sT # Portugal =================================================================== RCS file: RCS/northamerica,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- northamerica 2005/07/14 18:13:39 2005.10 +++ northamerica 2005/08/18 05:36:46 2005.10.0.1 @@ -116,15 +116,14 @@ Rule US 1918 1919 - Oct lastSun 2:00 0 S Rule US 1942 only - Feb 9 2:00 1:00 W # War Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace Rule US 1945 only - Sep 30 2:00 0 S -Rule US 1967 max - Oct lastSun 2:00 0 S +Rule US 1967 2006 - Oct lastSun 2:00 0 S Rule US 1967 1973 - Apr lastSun 2:00 1:00 D Rule US 1974 only - Jan 6 2:00 1:00 D Rule US 1975 only - Feb 23 2:00 1:00 D Rule US 1976 1986 - Apr lastSun 2:00 1:00 D -Rule US 1987 max - Apr Sun>=1 2:00 1:00 D -# <a href="http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.00177:"> -# H.R.177 -# </a> (introduced 1999-01-06) would change April to March in the above rule. +Rule US 1987 2006 - Apr Sun>=1 2:00 1:00 D +Rule US 2007 max - Mar Sun>=8 2:00 1:00 D +Rule US 2007 max - Nov Sun>=1 2:00 0 S # From Bob Devine (1988-01-28): # ...Alaska (and Hawaii) had the timezone names changed in 1967. @@ -202,7 +201,26 @@ Rule US 1987 max - Apr Sun>=1 2:00 1:00 # Public law 106-564 (2000-12-23) introduced the abbreviation # "Chamorro Standard Time" for time in Guam and the Northern Marianas. # See the file "australasia". - + +# From Arthur David Olson, 2005-08-09 +# The following was signed into law on 2005-08-08. +# +# H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS. +# (a) Amendment- Section 3(a) of the Uniform Time Act of 1966 (15 +# U.S.C. 260a(a)) is amended-- +# (1) by striking `first Sunday of April' and inserting `second +# Sunday of March'; and +# (2) by striking `last Sunday of October' and inserting `first +# Sunday of November'. +# (b) Effective Date- Subsection (a) shall take effect 1 year after the +# date of enactment of this Act or March 1, 2007, whichever is later. +# (c) Report to Congress- Not later than 9 months after the effective +# date stated in subsection (b), the Secretary shall report to Congress +# on the impact of this section on energy consumption in the United +# States. +# (d) Right to Revert- Congress retains the right to revert the +# Daylight Saving Time back to the 2005 time schedules once the +# Department study is complete. # US eastern time, represented by New York @@ -485,18 +503,19 @@ Zone America/Boise -7:44:49 - LMT 1883 N # # Most of EST-only Indiana last observed DST in 1970. -# From Paul Eggert (2001-03-06), following a tip by Markus Kuhn: -# Pam Belluck reported in the New York Times (2001-01-31) that the -# Indiana Legislature is considering a bill to adopt DST statewide. -# Her article mentioned Vevay, whose post office observes a different -# time zone from Danner's Hardware across the street. +# From Paul Eggert (2005-08-16): +# http://www.mccsc.edu/time.html says that Indiana will use DST starting 2006, +# and that many counties may switch either to Central or to Eastern time. +# The county-by-county decisions have not been made yet, so for now assume +# that no counties will switch: this assumption is most likely wrong, +# but it's the best we can do for now. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:15:22 +Zone America/Indiana/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:15:22 -6:00 US C%sT 1920 -6:00 Indianapolis C%sT 1942 -6:00 US C%sT 1946 @@ -505,8 +524,8 @@ Zone America/Indianapolis -5:44:38 - LMT -6:00 - CST 1958 Apr 27 2:00 -5:00 - EST 1969 -5:00 US E%sT 1971 - -5:00 - EST -Link America/Indianapolis America/Indiana/Indianapolis + -5:00 - EST 2006 + -5:00 US E%sT # # Part of Crawford County, Indiana, last observed DST in 1975, # and left its clocks alone in 1974. @@ -523,7 +542,8 @@ Zone America/Indiana/Marengo -5:45:23 - -5:00 US E%sT 1974 Jan 6 2:00 -6:00 1:00 CDT 1974 Oct 27 2:00 -5:00 US E%sT 1976 - -5:00 - EST + -5:00 - EST 2006 + -5:00 US E%sT # # Starke County, Indiana # From Arthur David Olson (1991-10-28): @@ -542,7 +562,8 @@ Zone America/Indiana/Knox -5:46:30 - LMT -6:00 Starke C%sT 1962 Apr 29 2:00 -5:00 - EST 1963 Oct 27 2:00 -6:00 US C%sT 1991 Oct 27 2:00 - -5:00 - EST + -5:00 - EST 2006 + -5:00 US E%sT # # Switzerland County, Indiana, last observed DST in 1972. # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -550,7 +571,8 @@ Zone America/Indiana/Vevay -5:40:16 - LM -6:00 US C%sT 1954 Apr 25 2:00 -5:00 - EST 1969 -5:00 US E%sT 1973 - -5:00 - EST + -5:00 - EST 2006 + -5:00 US E%sT # Part of Kentucky left its clocks alone in 1974. # This also includes a part of Indiana immediately adjacent to Louisville. @@ -563,7 +585,7 @@ Rule Louisville 1946 only - Jun 2 2:00 0 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone America/Louisville -5:43:02 - LMT 1883 Nov 18 12:16:58 +Zone America/Kentucky/Louisville -5:43:02 - LMT 1883 Nov 18 12:16:58 -6:00 US C%sT 1921 -6:00 Louisville C%sT 1942 -6:00 US C%sT 1946 @@ -572,7 +594,6 @@ Zone America/Louisville -5:43:02 - LMT 1 -5:00 US E%sT 1974 Jan 6 2:00 -6:00 1:00 CDT 1974 Oct 27 2:00 -5:00 US E%sT -Link America/Louisville America/Kentucky/Louisville # # Wayne, Clinton, and Russell Counties, Kentucky # @@ -1294,8 +1315,6 @@ Zone America/Dawson_Creek -8:00:56 - LMT # </a> (1999) reports that Pangnirtung operates on eastern time, # and that Coral Harbour does not observe DST. We don't know when # Pangnirtung switched to eastern time; we'll guess 1995. -# We'll ignore the claim about Coral Harbour for now, -# since we have no further info. # From Rives McDow (1999-11-08): # On October 31, when the rest of Nunavut went to Central time, @@ -1370,6 +1389,23 @@ Zone America/Dawson_Creek -8:00:56 - LMT # more. # [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).] +# From Gwillim Law (2005-05-21): +# According to maps at +# http://inms-ienm.nrc-cnrc.gc.ca/images/time_services/TZ01SWE.jpg +# http://inms-ienm.nrc-cnrc.gc.ca/images/time_services/TZ01SSE.jpg +# (both dated 2003), and +# http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp +# (from a 1998 Canadian Geographic article), the de facto and de jure time +# for Southampton Island (at the north end of Hudson Bay) is UTC-5 all year +# round. Using Google, it's easy to find other websites that confirm this. +# I wasn't able to find how far back this time regimen goes, but since it +# predates the creation of Nunavut, it probably goes back many years.... +# The Inuktitut name of Coral Harbour is Sallit, but it's rarely used. +# +# From Paul Eggert (2005-07-26): +# For lack of better information, assume that Southampton Island observed +# daylight saving only during wartime. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule NT_YK 1918 only - Apr 14 2:00 1:00 D Rule NT_YK 1918 only - Oct 27 2:00 0 S @@ -1393,6 +1429,9 @@ Zone America/Iqaluit -4:33:52 - LMT 1884 -5:00 NT_YK E%sT 1999 Oct 31 2:00 -6:00 Canada C%sT 2000 Oct 29 2:00 -5:00 Canada E%sT +Zone America/Coral_Harbour -5:32:40 - LMT 1884 + -5:00 NT_YK E%sT 1946 + -5:00 - EST Zone America/Rankin_Inlet -6:08:40 - LMT 1884 -6:00 NT_YK C%sT 2000 Oct 29 2:00 -5:00 - EST 2001 Apr 1 3:00 @@ -1968,10 +2007,21 @@ Zone America/Montserrat -4:08:52 - LMT 1 # The Decree, no 23-2005 is available here: # http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2005/Decreto%2023… # -# From Paul Eggert (2005-04-12): +# From Paul Eggert (2005-05-01): # The decree doesn't say anything about daylight saving, but for now let's # assume that it is daylight saving and that they'll switch back on the -# 2nd Sunday in September. +# 3rd Sunday in September. +# +# From Gwillim Law (2005-04-21): +# The Associated Press story on the time change, which can be found at +# http://www.lapalmainteractivo.com/guias/content/gen/ap/America_Latina/AMC_G… +# and elsewhere, says (fifth paragraph, translated from Spanish): "The last +# time that a change of clocks was applied to save energy was in the year 2000 +# during the Arnoldo Aleman administration."... +# The northamerica file says that Nicaragua has been on UTC-6 continuously +# since December 1998. I wasn't able to find any details of Nicaraguan time +# changes in 2000. Perhaps a note could be added to the northamerica file, to +# the effect that we have indirect evidence that DST was observed in 2000. # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D @@ -1979,7 +2029,7 @@ Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 Rule Nic 1992 only - Jan 1 4:00 1:00 D Rule Nic 1992 only - Sep 24 0:00 0 S Rule Nic 2005 only - Apr 10 0:00 1:00 D -Rule Nic 2005 only - Sep 11 0:00 0 S +Rule Nic 2005 only - Sep 18 0:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Managua -5:45:08 - LMT 1890 -5:45:12 - MMT 1934 Jun 23 # Managua Mean Time? =================================================================== RCS file: RCS/southamerica,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- southamerica 2005/07/14 18:13:40 2005.10 +++ southamerica 2005/08/18 05:36:46 2005.10.0.1 @@ -293,7 +293,7 @@ Zone America/Argentina/Jujuy -4:21:12 - -4:00 Arg AR%sT 2000 Mar 3 -3:00 - ART # -# Catamarca (CT) +# Catamarca (CT), Chubut (CH) Zone America/Argentina/Catamarca -4:23:08 - LMT 1894 Oct 31 -4:16:48 - CMT 1920 May -4:00 - ART 1930 Dec @@ -323,20 +323,6 @@ Zone America/Argentina/Mendoza -4:35:16 -4:00 - WART 2004 Sep 26 -3:00 - ART # -# Chubut (CH) -# The name "Comodoro Rivadavia" exceeds the 14-byte POSIX limit. -Zone America/Argentina/ComodRivadavia -4:30:00 - LMT 1894 Oct 31 - -4:16:48 - CMT 1920 May - -4:00 - ART 1930 Dec - -4:00 Arg AR%sT 1969 Oct 5 - -3:00 Arg AR%sT 1991 Mar 3 - -4:00 - WART 1991 Oct 20 - -3:00 Arg AR%sT 1999 Oct 3 - -4:00 Arg AR%sT 2000 Mar 3 - -3:00 - ART 2004 Jun 1 - -4:00 - WART 2004 Jun 20 - -3:00 - ART -# # Santa Cruz (SC) Zone America/Argentina/Rio_Gallegos -4:36:52 - LMT 1894 Oct 31 -4:16:48 - CMT 1920 May # Cordoba Mean Time =================================================================== RCS file: RCS/tz-link.htm,v retrieving revision 2005.8 retrieving revision 2005.8.0.1 diff -pu -r2005.8 -r2005.8.0.1 --- tz-link.htm 2005/04/04 15:24:34 2005.8 +++ tz-link.htm 2005/08/18 05:36:46 2005.8.0.1 @@ -30,8 +30,11 @@ The public-domain time zone database con 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 <abbr title="Coordinated Universal Time">UTC</abbr> -offsets and daylight-saving rules. +to <a href="http://en.wikipedia.org/wiki/Time_zone">time zone</a> +boundaries, <a href="http://en.wikipedia.org/wiki/UTC"><abbr +title="Coordinated Universal Time">UTC</abbr></a> offsets, and +<a href="http://en.wikipedia.org/wiki/Daylight_saving">daylight-saving</a> +rules. This database (often called <code>tz</code> or <code>zoneinfo</code>) is used by several implementations, including @@ -67,7 +70,7 @@ eastern time but with different <abbr>DS and other entries represent smaller regions like Starke County, Kentucky, which switched from central to eastern time in 1991. To use the database on an extended <a -href="http://www.pasc.org/#POSIX"><abbr +href="http://en.wikipedia.org/wiki/POSIX"><abbr title="Portable Operating System Interface">POSIX</abbr></a> implementation set the <code>TZ</code> environment variable to the location's full name, e.g., <code>TZ="America/New_York"</code>.</p> @@ -119,6 +122,7 @@ throughout the world.</li> <li><a href="http://www.convertit.com/Go/ConvertIt/World_Time/Current_Time.ASP">Current Time in 1000 Places</a></li> +<li><a href="http://time.world-stay.com/">The time around the world</a></li> <li><a href="http://timezoneconverter.com/">Time Zone Converter</a></li> </ul></li> <li><a href="http://www.timeanddate.com/worldclock/">The World Clock - @@ -147,15 +151,14 @@ title="Resource Description Framework">R and group scheduling systems, and has a <a href="http://www.w3.org/2002/12/cal/#tzd">workspace on time zone data</a> converted from <code>tz</code>. An earlier <a -href="http://www.w3.org/2000/01/foo">schema</a> was sketched out by <a -href="http://www.w3.org/People/Berners-Lee/">Tim Berners-Lee</a>.</li> +href="http://www.w3.org/2000/01/foo">schema</a> was sketched out.</li> <li><a -href="http://www.calsch.org/ietf/archives/draft-ietf-calsch-many-xcal-02.txt"><abbr -title="XML DTD for iCalendar">XCal</abbr></a> -was a draft <a +href="http://inet-consulting.com/draft-royer-calsch-xcal-01.txt"><abbr +title="iCalendar in XML Format">xCal</abbr></a> +is a draft <a href="http://www.w3.org/XML/"><abbr title="Extensible Markup Language">XML</abbr></a> document type -definition that corresponded to iCalendar.</li> +definition that corresponds to iCalendar.</li> </ul> <h2>Other <code>tz</code> compilers</h2> <ul> @@ -177,7 +180,7 @@ available under both the <abbr>GPL</abbr License. DateTime::TimeZone also contains a script <code>tests_from_zdump</code> that generates test cases for each clock transition in the <code>tz</code> database.</li> -<li><a href="http://oss.software.ibm.com/icu/"><abbr +<li><a href="http://ibm.com/software/globalization/icu"><abbr title="International Components for Unicode">ICU</abbr></a> contains a C/C++ library for internationalization that has a compiler from <code>tz</code> source @@ -209,20 +212,23 @@ This library is freely available under t and is widely used in <abbr>GNU</abbr>/Linux systems.</li> <li><a href="http://www.bmsi.com/java/#TZ">ZoneInfo.java</a> is a <code>tz</code> binary file reader written in Java. -It is freely available under the <abbr>GNU</abbr> -<abbr>LGPL</abbr>.</li> +It is freely available under the <abbr>LGPL</abbr>.</li> <li><a href="http://s.keim.free.fr/tz/doc.html">Python time zones</a> is a <code>tz</code> binary file reader written in Python. It is freely available under a <abbr>BSD</abbr>-style license.</li> </ul> -<h2>Other <code>tz</code>-based time zone conversion software</h2> +<h2>Other <code>tz</code>-based time zone software</h2> <ul> +<li><a href="http://freshmeat.net/projects/intclock">International +clock (intclock)</a> is a multi-timezone clock for +<abbr>GNU</abbr>/Linux and similar systems. It is freely available +under the <abbr>GPL</abbr>.</li> <li><a href="http://java.sun.com/">Sun Java</a> releases since 1.4 contain a copy of a subset of a recent <code>tz</code> database in a Java-specific format.</li> <li><a href="http://www1.tip.nl/~t876506/AboutTimeZonesHC.html">HyperCard -time zones calculator</a> is a HyperCard stack.</li> +time zones calculator</a> was a HyperCard stack.</li> <li><a href="http://www.veladg.com/velaterra.html">VelaTerra</a> is a Mac OS X program. Its developers @@ -295,7 +301,7 @@ world time zone boundaries distributed u <abbr>GPL</abbr>.</li> <li>The <abbr>US</abbr> Geological Survey's National Atlas of the United States -publishes the <a href="http://www.nationalatlas.gov/timeznm.html">Time +publishes the <a href="http://nationalatlas.gov/mld/timeznp.html">Time Zones of the United States</a> in the public domain.</li> <li>The GeoCommunity lists several commercial sources for <a href="http://spatialnews.geocomm.com/features/timezones/">International @@ -326,11 +332,12 @@ Zone Concepts</a> discusses terminologic <h2>National histories of legal time</h2> <dl> <dt>Australia</dt> -<dd>The Community Relations Division of the New South Wales -(<abbr title="New South Wales">NSW</abbr>) -Attorney General's Department maintains a <a -href="http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2">history of -daylight saving in <abbr>NSW</abbr></a>.</dd> +<dd>The Bureau of Metrology publishes a list of +<a href="http://www.bom.gov.au/climate/averages/tables/dst_times.shtml">Implementation Dates of Daylight Savings Time within Australia</a>. +The Community Relations Division of the New South Wales +Attorney General's Department maintains a history of <a +href="http://www.lawlink.nsw.gov.au/Lawlink/Corporate/ll_corporate.nsf/pages/atto…">Daylight +Saving in New South Wales</a>.</dd> <dt>Austria</dt> <dd>The Federal Office of Metrology and Surveying publishes a table of <a href="http://www.metrologie.at/pdf/sommerzeit.pdf" @@ -375,10 +382,15 @@ hreflang="nl">Legal time in the Netherla covers the history of local time in the Netherlands from ancient times.</dd> <dt>New Zealand</dt> <dd>The Department of Internal Affairs maintains a brief history <a -href="http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Resource-material-Information…">about -daylight saving</a>. The privately-maintained <a -href="http://www.astrologyhouse.co.nz/timechanges.htm">Time Changes in -New Zealand</a> has more details.</dd> +href="http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Resource-material-Information…">About +Daylight Saving</a>. The privately-maintained <a +href="http://www.astrologyschool.com/nztime.html">History of New Zealand +time</a> has more details.</dd> +<dt>Norway</dt> +<dd>The Norwegian Meteorological Institute lists +<a href="http://met.no/met/met_lex/q_u/sommertid.html" hreflang="no">Summer +time in Norway (in Norwegian)</a>, citing the +Institute of Theoretical Astrophysics, Oslo.</dd> <dt>Singapore</dt> <dd><a href="http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html">Why @@ -390,8 +402,8 @@ href="http://www.srcf.ucam.org/~jsm28/br legal time in Britain</a> discusses in detail the country with perhaps the best-documented history of clock adjustments. The National Physical Laboratory also maintains an <a -href="http://www.npl.co.uk/time/summer_time_archive.html">archive -of summer time dates</a>.</dd> +href="http://www.npl.co.uk/time/summer_time_archive.html">Archive +of Summer time dates</a>.</dd> </dl> <h2>Precision timekeeping</h2> <ul> @@ -411,7 +423,7 @@ the <abbr title="Royal Greenwich Observa answers questions like "What is the difference between <abbr>GMT</abbr> and <abbr>UTC</abbr>?"</li> <li><a -href="http://www.gb.nrao.edu/~rfisher/Ephemerides/times.html">Astronomical +href="http://www.cv.nrao.edu/~rfisher/Ephemerides/times.html">Astronomical Times</a> explains more abstruse astronomical time scales like <abbr title="Terrestrial Dynamic Time">TDT</abbr>, <abbr title="Geocentric Coordinate Time">TCG</abbr>, and @@ -446,7 +458,8 @@ International Earth Rotation Service, th when leap seconds occur.</li> <li>The <a href="http://www.mail-archive.com/leapsecs@rom.usno.navy.mil/">Leap -Second Discussion List</a> covers <a +Second Discussion List</a> and <a +href="http://rom.usno.navy.mil/archives/leapsecs.html">archive</a> covers <a href="http://gauss.gge.unb.ca/papers.pdf/gpsworld.november99.pdf">McCarthy and Klepczynski's proposal to discontinue leap seconds</a>, published in <a href="http://www.gpsworld.com/"><abbr @@ -489,9 +502,8 @@ protocols.</li> Best of Dates, the Worst of Dates</a> covers many problems encountered by software developers when handling dates and time stamps.</li> <li><a -href="http://ibm.com/software/globalization/icu"><abbr -title="International Components for Unicode">ICU</abbr></a> contains a -mechanism for localizing time zone +href="http://ibm.com/software/globalization/icu"><abbr>ICU</abbr></a> +contains a mechanism for localizing time zone labels and abbreviations; for example, one can use it to specify Russian translations for "Eastern European Summer Time", "<abbr title="Eastern European Summer Time">EEST</abbr>", @@ -500,8 +512,7 @@ This mechanism is part of the <a href="http://unicode.org/cldr/">Unicode <abbr title="Common Locale Data Repository">CLDR</abbr> Project</a>; for example, the <a -href="http://www.unicode.org/cldr/data/diff/by_type/dates_timeZoneNames.html">By-Type -Chart for //ldml/dates/timeZoneNames/…</a> +href="http://unicode.org/cldr/data/diff/by_type/dates_timeZoneNames.html"><abbr>CLDR</abbr> Sideways Data for dates_timeZoneNames</a> shows values for time zone names in many locales.</li> <li>Alphabetic time zone abbreviations should not be used as unique identifiers for <abbr>UTC</abbr> offsets as they are ambiguous in @@ -523,7 +534,7 @@ example, one might use <code>TZ="JST-9"< <code>tz</code> database is available, it is usually better to use settings like <code>TZ="Asia/Tokyo"</code> and <code>TZ="Pacific/Honolulu"</code> instead, as this should avoid -confusion, handle old timestamps better, and insulate you better from +confusion, handle old time stamps better, and insulate you better from any future changes to the rules. One should never set <abbr>POSIX</abbr> <code>TZ</code> to a value like <code>"GMT-9"</code>, though, since this would falsely claim that @@ -538,7 +549,7 @@ Reference: Time</a></li> <li><a href="http://directory.google.com/Top/Reference/Time/">Google Directory - Reference > Time</a></li> <li><a href="http://dir.yahoo.com/Science/Measurements_and_Units/Time/">Yahoo! -Science > Measurements and Units > Time</a></li> +Directory > Science > Measurements and Units > Time</a></li> </ul> </body> </html> =================================================================== RCS file: RCS/zone.tab,v retrieving revision 2005.10 retrieving revision 2005.10.0.1 diff -pu -r2005.10 -r2005.10.0.1 --- zone.tab 2005/07/14 18:13:40 2005.10 +++ zone.tab 2005/08/18 05:36:46 2005.10.0.1 @@ -45,17 +45,17 @@ AR -3436-05827 America/Argentina/Buenos_ AR -3124-06411 America/Argentina/Cordoba most locations (CB, CC, CN, ER, FM, LP, MN, NQ, RN, SA, SE, SF, SL) AR -2411-06518 America/Argentina/Jujuy Jujuy (JY) AR -3124-06411 America/Argentina/Tucuman Tucuman (TM) -AR -2828-06547 America/Argentina/Catamarca Catamarca (CT) +AR -2828-06547 America/Argentina/Catamarca Catamarca (CT), Chubut (CH) AR -2926-06651 America/Argentina/La_Rioja La Rioja (LR) AR -3132-06831 America/Argentina/San_Juan San Juan (SJ) AR -3253-06849 America/Argentina/Mendoza Mendoza (MZ) -AR -4552-06730 America/Argentina/ComodRivadavia Chubut (CH) AR -5138-06913 America/Argentina/Rio_Gallegos Santa Cruz (SC) AR -5448-06818 America/Argentina/Ushuaia Tierra del Fuego (TF) AS -1416-17042 Pacific/Pago_Pago AT +4813+01620 Europe/Vienna AU -3133+15905 Australia/Lord_Howe Lord Howe Island -AU -4253+14719 Australia/Hobart Tasmania +AU -4253+14719 Australia/Hobart Tasmania - most locations +AU -3956+14352 Australia/Currie Tasmania - King Island AU -3749+14458 Australia/Melbourne Victoria AU -3352+15113 Australia/Sydney New South Wales - most locations AU -3157+14127 Australia/Broken_Hill New South Wales - Yancowinna @@ -107,9 +107,10 @@ CA +4531-07334 America/Montreal Eastern CA +4339-07923 America/Toronto Eastern Time - Ontario - most locations CA +4901-08816 America/Nipigon Eastern Time - Ontario & Quebec - places that did not observe DST 1967-1973 CA +4823-08915 America/Thunder_Bay Eastern Time - Thunder Bay, Ontario -CA +6608-06544 America/Pangnirtung Eastern Standard Time - Pangnirtung, Nunavut -CA +6344-06828 America/Iqaluit Eastern Standard Time - east Nunavut -CA +6245-09210 America/Rankin_Inlet Eastern Standard Time - central Nunavut +CA +6608-06544 America/Pangnirtung Eastern Time - Pangnirtung, Nunavut +CA +6344-06828 America/Iqaluit Eastern Time - east Nunavut +CA +6408-08310 America/Coral_Harbour Eastern Standard Time - Southampton Island +CA +6245-09210 America/Rankin_Inlet Central Time - central Nunavut CA +4953-09709 America/Winnipeg Central Time - Manitoba & west Ontario CA +4843-09429 America/Rainy_River Central Time - Rainy River & Fort Frances, Ontario CA +6903-10505 America/Cambridge_Bay Central Time - west Nunavut @@ -165,15 +166,13 @@ ET +0902+03842 Africa/Addis_Ababa FI +6010+02458 Europe/Helsinki FJ -1808+17825 Pacific/Fiji FK -5142-05751 Atlantic/Stanley -FM +0931+13808 Pacific/Yap Yap -FM +0725+15147 Pacific/Truk Truk (Chuuk) +FM +0725+15147 Pacific/Truk Truk (Chuuk) and Yap FM +0658+15813 Pacific/Ponape Ponape (Pohnpei) FM +0519+16259 Pacific/Kosrae Kosrae FO +6201-00646 Atlantic/Faeroe FR +4852+00220 Europe/Paris GA +0023+00927 Africa/Libreville -GB +512830-0001845 Europe/London Great Britain -GB +5435-00555 Europe/Belfast Northern Ireland +GB +512830-0001845 Europe/London GD +1203-06145 America/Grenada GE +4143+04449 Asia/Tbilisi GF +0456-05220 America/Cayenne @@ -248,8 +247,7 @@ MG -1855+04731 Indian/Antananarivo MH +0709+17112 Pacific/Majuro most locations MH +0905+16720 Pacific/Kwajalein Kwajalein MK +4159+02126 Europe/Skopje -ML +1239-00800 Africa/Bamako southwest Mali -ML +1446-00301 Africa/Timbuktu northeast Mali +ML +1239-00800 Africa/Bamako MM +1647+09610 Asia/Rangoon MN +4755+10653 Asia/Ulaanbaatar most locations MN +4801+09139 Asia/Hovd Bayan-Olgiy, Govi-Altai, Hovd, Uvs, Zavkhan @@ -370,9 +368,9 @@ UM +2813-17722 Pacific/Midway Midway Isl UM +1917+16637 Pacific/Wake Wake Island US +404251-0740023 America/New_York Eastern Time US +421953-0830245 America/Detroit Eastern Time - Michigan - most locations -US +381515-0854534 America/Louisville Eastern Time - Kentucky - Louisville area +US +381515-0854534 America/Kentucky/Louisville Eastern Time - Kentucky - Louisville area US +364947-0845057 America/Kentucky/Monticello Eastern Time - Kentucky - Wayne County -US +394606-0860929 America/Indianapolis Eastern Standard Time - Indiana - most locations +US +394606-0860929 America/Indiana/Indianapolis Eastern Standard Time - Indiana - most locations US +382232-0862041 America/Indiana/Marengo Eastern Standard Time - Indiana - Crawford County US +411745-0863730 America/Indiana/Knox Eastern Standard Time - Indiana - Starke County US +384452-0850402 America/Indiana/Vevay Eastern Standard Time - Indiana - Switzerland County

1 0

Re: Proposed change for new U. S. law; also, what about Indiana?
by Paul Eggert Aug. 17, 2005

Aug. 17, 2005

> Date: Fri, 12 Aug 2005 22:25:41 -0400 > From: John Hawkinson <jhawk(a)MIT.EDU> > > [ I had originally sent a version of this on Tuesday morning, but it > failed to go through because apparently lecserver.nci.nih.gov is still > firewalled, and elsie works only because of an MX record. ] Yes, things are still much messed up for me as well. I am getting no copies of email (I had to FTP the mail archive from elsie to see your mail). Also, the email headers get rewritten to be from tz(a)lecserver.nci.nih.gov, so when people reply to email their messages do not get through. Perhaps we should move the list elsewhere? I can volunteer the GNU email server <http://lists.gnu.org/>, if that would help. > HR numbers are per-year (e.g. HR.6 of the 109th Congress), and are > really only useful before bills become laws. I expect it will be > assigned a Public Law number sometime this coming week, and that will > appear at "http://thomas.loc.gov/cgi-bin/bdquery/z?d109:HR00006:@@@S". > > Can we wait until then and include that number? I wouldn't wait. We can update the comment later. > p.s.: I keep wondering if its a good time to propose changing the > default name of US timezones to US/Eastern -style rather than > America/New_York, because our timezones are set based on national > policy Unfortunately that's not quite true. The daylight-saving rules are national policy, but whether to adopt daylight-saving is decided more locally. (Speaking of which, what is the story on Indiana? <http://www.perrycountynews.com/articles/2005/08/15/top_story/t1.txt> says that Indiana will observe DST starting next year. Is that really true?) Also, time zone boundaries move. So, for example, US/Eastern is not correct for Monticello, KY, as it will mishandle time stamps before 2000 (Monticello switched from Central to Eastern in fall 2000). We will continue to support names like US/Eastern indefinitely, but the location-based names are more accurate.

3 4

Re: Web page updates
by Paul Eggert Aug. 16, 2005

Aug. 16, 2005

Thanks for the link updates. I'll let Arthur handle the tz-art.htm change. For tz-link.htm you write: > The link http://www.astrologyhouse.co.nz/timechanges.htm does not exist > anymore, and I can not find a relocated page at the web site. Please see <http://www.astrologyschool.com/nztime.html>. > The link http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 does not > exist anymore, and I can not find a relocated page at the web site. Please see <http://www.bom.gov.au/climate/averages/tables/dst_times.shtml>. > The link http://www.nationalatlas.gov/timeznm.html does not exist > anymore. http://nationalatlas.gov/mld/timeznp.html seems to be a > suitable replacement. Yes, thanks, I found that one just a few hours ago myself. I'll propose a patch for these (and other) problems soon.

1 0

Re: Multi-timezone clock
by Paul Eggert Aug. 16, 2005

Aug. 16, 2005

peter.verthez(a)alcatel.be writes: > http://freshmeat.net/projects/intclock Thanks for letting us know about that; I'll add a reference in my next proposed tz patch. I use Debian, so I hope intclock gets added as a Debian package some day.

1 0

Re: Request from CLDR committee
by Paul Eggert Aug. 16, 2005

Aug. 16, 2005

> From: "Mark Davis" <mark.davis(a)icu-project.org> > Sent: Tuesday, August 09, 2005 07:28 > > 1. Missing Country Codes. > ... > Suggested changes: > To antarctica, add > Zone Atlantic/Bouvet 0:00 - GMT > Zone Pacific/Heard 5:00 - GMT The problem with this approach, as I see it, is that the data are purely invented. Heard Island is not 5 hours ahead of GMT, since nobody lives there. In a practical sense, local time is undefined for uninhabited locations, and it would be misleading for the tz database to imply otherwise. I suppose we could work around this by using a "zzz" entry, e.g.: Zone Indian/Heard 0:00 - zzz but I wonder whether this might cause more troubles than it'd cure. "zzz" currently is used to denote local time for locations that are sometimes inhabited and sometimes uninhabited. However, this is a hack: what is really wanted is a relation where the entries for local time are simply absent while the location is uninhabited. As far as I can tell, the country codes HM and BV are ISO 3166 curiosities. For example, www.bv is now owned by Black & Veatch, a privately-held firm that two of my cousins work for -- it has nothing to do with Bouvet Island. I wouldn't worry too much about these glitches in the ISO database. > 2. Enabling Canonical IDs > > One dependency we have is that the last field in the canonical ID be unique. > That is, we can't have both a Europe/London and an America/London. I wouldn't rely on this. It's too constraining on the database. Part of the point of having a tree-structured name space is the desire to avoid constraints like these. > This appears to be the practice in > the TZ database, as evidenced by the following in southamerica: > > # Bahia (BA) > # There are too many Salvadors elsewhere, so use America/Bahia instead > # of America/Salvador. That comment refers to the other Salvadors in America. If there were a Salvador in Africa (or even in America/Argentina) it wouldn't be a problem. > We also depend on the feature that every equivalence class (except Etc/...) > has exactly one member in zone.tab. That sounds reasonable. How about if we add something to Theory saying that zone.tab "is intended to be an exhaustive list of canonical names for geographic regions." > List A. TZIDs that are not linked, but are the same > > 001 Etc/GMT > 001 Etc/UTC > 001 Etc/UCT -- not linked, identical They are not identical, since they use different abbreviations. Hence they cannot be linked. For example, on my Debian GNU/Linux 3.1 box: $ TZ=Etc/GMT date Tue Aug 16 17:31:23 GMT 2005 $ TZ=Etc/UTC date Tue Aug 16 17:31:27 UTC 2005 The difference in output is intentional. How about if you simplify your life by simply ignoring the Etc/* names? > List B. TZIDs that are not linked, are different locations, but are the same > since 1970 > > AQ Antarctica/Mawson > AQ Antarctica/Vostok -- same since 57 As far as I know it's merely a coincidence that the two bases use the same time zone. Most crucially the bases belong to different countries (so to some extent the "different country" rule applies, though admittedly Antarctica is special) and use different supply lines. I'd rather leave them alone for now. > FM Pacific/Truk > FM Pacific/Yap -- same since 70 > GB Europe/Belfast > GB Europe/London -- same since 68 > ML Africa/Bamako > ML Africa/Timbuktu -- same since 60 OK, let's merge those. It is more consistent to do so. We'll keep backward-compatibility entries, of course. Sigh. I sort of liked having Timbuktu in the database. > List C. TZIDs that are linked, but refer to different locations. As a rule, these locations have identical time zone histories except before the advent of standard time; and LMT (by definition) is approximate, so I don't see the harm in keeping them linked. If they are trouble for your system, perhaps you can keep a list of exceptions and filter them out. That being said, perhaps some of the "Link" lines should be moved from northamerica (etc.) to backward. For example, the line Link America/New_York EST5EDT is in the "northamerica" file, but it's really there only for backward compatibility with System V, so perhaps we should move it to "backward". Arthur, would you be open to that sort of thing?

1 0