- tz - lists.iana.org

Re: Shank's International Atlas
by ado Oct. 20, 1993

Oct. 20, 1993

Some initial feedback. 1. The notion in the README file is that > Historical local time information has been included here not because it > is particularly useful, but rather to: > > * give an idea of the variety of local time rules that have > existed in the past and thus an idea of the variety that may be > expected in the future; > > * provide a test of the generality of the local time rule description > system. That being so, we'd want to be on the lookout for rare timekeeping changes and be sure to include them. 2. A pragmatic answer to how many zones to have for France is "as many as are needed to describe the present day zones." As you noted, though, doing even this at the country level yields lots of zones. 3. As a last resort, simply reporting UCT for a zone when it's doing something awkward is a possibility. --ado

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Shanks's International Atlas [forwarded with permission from eggert@twinsun.com]
by ado Oct. 20, 1993

Oct. 20, 1993

> From twinsun!twinsun.com!eggert(a)CS.UCLA.EDU Tue Oct 19 15:08:13 1993 > Return-Path: <twinsun!twinsun.com!eggert(a)CS.UCLA.EDU> > ... > From: eggert(a)twinsun.com (Paul Eggert) > Message-Id: <9310191858.AA24533(a)spot.twinsun.com> > Date: 19 Oct 1993 11:58:24 -0700 > To: ado(a)elsie.nci.nih.gov > Subject: Shanks's International Atlas > ... > > In looking through Shanks's atlas I see a number of points that perhaps need > further thinking before I sit down and try to generate more tables. The main > point is that we need to decide what the limitations of the tz database should > be. I'd appreciate your advice on the following points, which are roughly in > decreasing order of seriousness. > > There are many, many tables. E.g. France has 153 tables; most of the variants > occurred during World War II, as the fortunes of war caused different > districts to switch between French and German time zone rules. Do we really > want a directory labeled `France' with 153 files in it, one per district? > Even coming up with the district names will be a chore, as Shanks merely gives > each table a number and, for each city, tells you which time table it uses. > > Even the number of countries would mean that the timezone database would be > very bushy at top level, with entries ranging from Afghanistan to Zimbabwe. > Perhaps some substructure is in order. At some point you mentioned using ISO > country codes? (But how many people know their country code?) > > The current code makes no provision for when a district changed from LMT to > standard time (e.g. 1914 Jan 1 in Albania). Strictly speaking, it's incorrect > to give times other than LMT before the switch. At least we should put in a > comment when LMT began, I suppose. But should there be some provision in the > code as well? I suppose it would be something like a suffix to the TZ value > which specifies the LMT offset when LMT is in effect, since you can't possibly > have a table for each LMT offset. > > I doubt whether the following points are worth worrying about in the code, > but perhaps there should be a commenting convention for documenting these > points. > > Some countries switched from the Gregorian to the Julian calendar in this > century; e.g. part of Bulgaria held out until 1920 Sept 17 (Gregorian). I > suppose this is too much for the TZ code to handle, but perhaps comments are > in order. > > The Soviet Union instituted a 5 day week in 1929, a 6 day week in 1932, and > reverted to a 7 day week in 1940. > > China changed from the Chinese calendar on 1912 Feb 12 (Gregorian); > Japan from the Japanese calendar on 1893 Jan 1 (Gregorian). > > There was a time before LMT, when people used apparent time, not mean time. > E.g. Paris switched from apparent time to LMT in 1816.

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Re: Shank's International Atlas, with GB-Eire as a test case
by ado Oct. 15, 1993

Oct. 15, 1993

Paul Eggert's changes are now incorporated in the files tzcode93f.tar.Z and tzdata93f.tar.Z in the ~ftp/pub directory of elsie.nci.nih.gov (128.231.16.1). Thanks to Paul Eggert for the information! --ado

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Shank's International Atlas, with GB-Eire as a test case
by eggert＠twinsun.com Oct. 15, 1993

Oct. 15, 1993

I just found the book Thomas G. Shanks The International Atlas (3rd ed) San Diego: ACS Publications, Inc. (1991) xx + 428 pp. ISBN 0-935127-16-X, $36, order phone: +1 800 888 9983 which lists detailed historical time zone data, plus latitude and longitude, for places all over the world. For example, for Germany it lists over 20 pages of data in fine print, of which one page contains seven different historical time zone regions and the complete history of all GMT offsets in each region since the 1890s (when Germany started using standard time). There's a separate atlas (which I don't have) for US time zone data. ACS Publications serves astrologers, who seem to be the folks who care most about historical time zone data. (You get a 20% discount on your second order if you tell them your sun sign!) To see if it was good stuff, I checked Shanks's book vs the tz1993d rules for Great Britain and Eire. In nearly every case where Shanks disagreed with tz1993d, it seems to me that Shanks is more likely to be correct. The discrepancies included the following: * transcription errors in 1916, 1923, and 1968, where the tz1993d data doesn't match Peter Ilieve's transcription of the UK Government paper "Summer Time: A Consultation Document". * Shanks says summer time began in 1924 in 13 April, which seems far more likely to be correct than Ilieve's 30 April, since 30 April 1924 was a Wednesday. * Shanks says Eire did not observe war time during World War II, which seems likely since Eire was neutral. He says that Eire stayed an hour ahead of GMT through the war, and then had its own summer time scheme until 1948 when it reverted to GB time. * Shanks says Eire was 25 minutes behind GMT until 1916, switched to 35 minutes ahead of GMT during summer 1916, and then switched the clocks twice (!) on the morning of 1 Oct 1916, first to 1 hour ahead of GMT, then (35 minutes later) to GMT. This is the only hard-to-believe part of Shanks's data, but it's just crazy enough to be true. That last bit exposed another zdump bug: if the clock changes more than once in the same 12-hour period it sometimes misses some of the changes. I doubt whether Shanks is infallible -- his data for Israel looks funny, and he doesn't agree with the stories I've heard about the Soviet Union in the 1930s -- but it does seem like a good source, at least for those parts of the world where horoscopes are popular. Here's a proposed patch. =================================================================== RCS file: RCS/zdump.c,v retrieving revision 7.7 retrieving revision 7.7.1.1 diff -c -r7.7 -r7.7.1.1 *** zdump.c 1993/09/06 01:21:19 7.7 --- zdump.c 1993/10/15 00:18:49 7.7.1.1 *************** *** 82,88 **** static char * abbr(); static long delta(); ! static void hunt(); static int longest; static char * progname; static void show(); --- 82,88 ---- static char * abbr(); static long delta(); ! static time_t hunt(); static int longest; static char * progname; static void show(); *************** *** 177,183 **** if (delta(&newtm, &tm) != (newt - t) || newtm.tm_isdst != tm.tm_isdst || strcmp(abbr(&newtm), buf) != 0) { ! hunt(argv[i], t, newt); (void) strncpy(buf, abbr(&newtm), (sizeof buf) - 1); } --- 177,184 ---- if (delta(&newtm, &tm) != (newt - t) || newtm.tm_isdst != tm.tm_isdst || strcmp(abbr(&newtm), buf) != 0) { ! newt = hunt(argv[i], t, newt); ! newtm = *localtime(&newt); (void) strncpy(buf, abbr(&newtm), (sizeof buf) - 1); } *************** *** 208,214 **** ; } ! static void hunt(name, lot, hit) char * name; time_t lot; --- 209,215 ---- ; } ! static time_t hunt(name, lot, hit) char * name; time_t lot; *************** *** 237,242 **** --- 238,244 ---- } show(name, lot, TRUE); show(name, hit, TRUE); + return hit; } /* =================================================================== RCS file: RCS/europe,v retrieving revision 7.5 retrieving revision 7.5.1.1 diff -c -r7.5 -r7.5.1.1 *** europe 1993/09/06 01:21:38 7.5 --- europe 1993/10/15 00:19:31 7.5.1.1 *************** *** 7,12 **** --- 7,16 ---- # ahead and edit the file (and please send any changes to # ado(a)ncifcrf.gov for general use in the future). + # A good source for time zone historical data outside the U.S. is + # Thomas G. Shanks, The International Atlas (3rd edition), + # San Diego: ACS Publications, Inc. (1991). + ############################################################################### # United Kingdom *************** *** 52,58 **** # 1921 3 April 3 October # 1922 26 March 8 October # 1923 22 April 16 September ! # 1924 30 April 21 September # 1925 to 3rd Sunday 1st Sunday # 1938 in April in October # --- 56,62 ---- # 1921 3 April 3 October # 1922 26 March 8 October # 1923 22 April 16 September ! # 1924 13 April 21 September # 1925 to 3rd Sunday 1st Sunday # 1938 in April in October # *************** *** 120,125 **** --- 124,139 ---- # # These dates agree with the ones from Whitaker's Almanac for 1960--87. . . + # From Paul Eggert (October 14, 1993) + # + # I changed the date `30 April 1924' to `13 April 1924' in the above table + # to fix what must be transcription error, since 30 April is not a Sunday, + # and Shanks gives 13 April which is a Sunday. + # + # The rules for Eire below are taken from Shanks, and reflect his claim that + # Eire changed the clock twice on 1 Oct 1916. I invented `IST' and `IDT' as + # abbreviations for Eire's standard and daylight time before 1 Oct 1916. + # From Arthur David Olson (January 19, 1989): # # A source at the British Information Office in New York avers that it's *************** *** 210,216 **** # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S # 1916 to 1925--irregular ! Rule GB-Eire 1916 only - Mar 21 2:00s 1:00 BST Rule GB-Eire 1916 only - Oct 1 2:00s 0 GMT Rule GB-Eire 1917 only - Apr 8 2:00s 1:00 BST Rule GB-Eire 1917 only - Sep 17 2:00s 0 GMT --- 224,230 ---- # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S # 1916 to 1925--irregular ! Rule GB-Eire 1916 only - May 21 2:00s 1:00 BST Rule GB-Eire 1916 only - Oct 1 2:00s 0 GMT Rule GB-Eire 1917 only - Apr 8 2:00s 1:00 BST Rule GB-Eire 1917 only - Sep 17 2:00s 0 GMT *************** *** 225,232 **** Rule GB-Eire 1922 only - Mar 26 2:00s 1:00 BST Rule GB-Eire 1922 only - Oct 8 2:00s 0 GMT Rule GB-Eire 1923 only - Apr 22 2:00s 1:00 BST ! Rule GB-Eire 1923 only - Oct 16 2:00s 0 GMT ! Rule GB-Eire 1924 only - Apr 30 2:00s 1:00 BST Rule GB-Eire 1924 only - Sep 21 2:00s 0 GMT # 1925 to 1939 start--regular Rule GB-Eire 1925 1939 - Apr Sun>=15 2:00s 1:00 BST --- 239,246 ---- Rule GB-Eire 1922 only - Mar 26 2:00s 1:00 BST Rule GB-Eire 1922 only - Oct 8 2:00s 0 GMT Rule GB-Eire 1923 only - Apr 22 2:00s 1:00 BST ! Rule GB-Eire 1923 only - Sep 16 2:00s 0 GMT ! Rule GB-Eire 1924 only - Apr 13 2:00s 1:00 BST Rule GB-Eire 1924 only - Sep 21 2:00s 0 GMT # 1925 to 1939 start--regular Rule GB-Eire 1925 1939 - Apr Sun>=15 2:00s 1:00 BST *************** *** 266,272 **** Rule GB-Eire 1960 only - Apr 10 2:00s 1:00 BST Rule GB-Eire 1961 1963 - Mar lastSun 2:00s 1:00 BST Rule GB-Eire 1964 1967 - Mar Sun>=19 2:00s 1:00 BST - Rule GB-Eire 1968 only - Feb 18 2:00s 1:00 BST Rule GB-Eire 1972 1980 - Mar Sun>=16 2:00s 1:00 BST # 1953 to 1980, ending rules Rule GB-Eire 1953 1960 - Oct Sun>=1 2:00s 0 GMT --- 280,285 ---- *************** *** 278,284 **** Rule GB-Eire 1981 max - Oct Sun>=23 1:00s 0 GMT # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] ! Zone GB-Eire 0:00 GB-Eire %s 1968 Oct 27 2:00s 1:00 - BST 1971 Oct 31 2:00s 0:00 GB-Eire %s --- 291,309 ---- Rule GB-Eire 1981 max - Oct Sun>=23 1:00s 0 GMT # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] ! Zone GB 0:00 - GMT 1916 May 21 2:00s ! 0:00 GB-Eire %s 1968 Feb 18 2:00s ! 1:00 - BST 1971 Oct 31 2:00s ! 0:00 GB-Eire %s ! Zone Eire -0:25 - IST 1916 May 21 2:00 ! -0:25 1:00 IDT 1916 Oct 1 2:00 ! 0:00 1:00 BST 1916 Oct 1 3:00 ! 0:00 GB-Eire %s 1940 Feb 25 2:00 ! 0:00 1:00 BST 1946 Oct 6 2:00 ! 0:00 - GMT 1947 Mar 16 2:00 ! 0:00 1:00 BST 1947 Nov 2 2:00 ! 0:00 - GMT 1948 Apr 18 2:00 ! 0:00 GB-Eire %s 1968 Feb 18 2:00s 1:00 - BST 1971 Oct 31 2:00s 0:00 GB-Eire %s

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Timezone info on BSDI Date & Time gateway
by bostic＠vangogh.CS.Berkeley.EDU Oct. 6, 1993

Oct. 6, 1993

>From sanders(a)BSDI.COM Tue Oct 5 19:42:36 1993 To: eng(a)BSDI.COM Subject: I knew this internet connection was good for something... Date: Tue, 05 Oct 1993 18:43:48 -0500 From: Tony Sanders <sanders(a)BSDI.COM> ------- Forwarded Message Received: from probitas.cs.utas.edu.au by austin.BSDI.COM (5.67/1.37) id AA09594; Tue, 5 Oct 93 18:21:17 -0500 Received: from brian.cs.utas.edu.au by probitas.cs.utas.edu.au (AIX 3.2/UCB 5.64/4.03) id AA41183; Wed, 6 Oct 1993 10:21:41 +1000 Message-Id: <9310060021.AA41183(a)probitas.cs.utas.edu.au> X-Sender: brian(a)probitas.cs.utas.edu.au Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 6 Oct 1993 10:21:10 +1000 To: sanders(a)www.bsdi.com From: Brian.Marriott(a)probitas.cs.utas.edu.au (Brian Marriott) Subject: Timezone info on BSDI Date & Time gateway Hi Tony I just had occasion to check the BSDI Date & Time gateway via www. Congratulations, it looks good - a great idea. You've got one minor thing wrong in your timezone info, though (through no fault of yours). The timezone for Tasmania, Australia shows currently as GMT+10, but it's actually at GMT+11. A recent bureaucratic decision means that Tasmania switches to daylight saving (GMT+11) on the first Sunday in October (at 0200, GMT+10), and switches back to Eastern Australian Standard Time (GMT+10) on the last Sunday in March (at 0200, GMT+11). You can't be expected to be aware of this, I know, because it was only recently announced here in Tasmania. Cheers, Brian Marriott (a non-animated Tasmanian Devil) - ------------------------------------------------------------- Brian Marriott AARNet: Brian.Marriott(a)cs.utas.edu.au Department of Computer Science University of Tasmania Phone: 002 202 929 Fax: 002 202 913 (Int'l +61 02 202 913) Postal address: GPO Box 252C, Hobart Tasmania 7001, Australia ------- End of Forwarded Message

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tzcode93e.tar.Z and tzdata93e.tar.Z
by ado Sept. 6, 1993

Sept. 6, 1993

Updated versions of the time zone stuff are available by anonymous ftp from elsie.nci.nih.gov (128.231.16.1); you'll want the files tzcode93e.tar.Z and tzdata93e.tar.Z from the "pub" directory. There's updated data for Israel, England, and Kwajalein; there's also an update to "zdump" to cope with Kwajalein's 24-hour jump. Thanks to Paul Eggert and Peter Ilieve for the changes. --ado

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latest entries for Israeli time zones
by eggert＠twinsun.com Sept. 5, 1993

Sept. 5, 1993

After I wrote a note in comp.risks about Solaris 2.2 time zone bugs, I got a message from Yitschak Goldberg <yits(a)eandm.co.il> that the latest Olson tables weren't right either. After asking around, Ephraim Silverberg kindly sent me his latest info; I enclose his note at the end of this message. So I propose the following patch to the `asia' file. ----- start of patch ----- =================================================================== RCS file: asia,v retrieving revision 7.4 retrieving revision 7.4.1.1 diff -c -r7.4 -r7.4.1.1 *** asia 1993/06/18 03:34:10 7.4 --- asia 1993/09/05 09:58:16 7.4.1.1 *************** *** 89,315 **** # year; as information, regarding exact times and dates during this period, # is not readily available at the present time, the rules commence starting # with the year 1989. - # - # From 1989 onwards the rules are as follows: - # - # 1. Daylight Savings Time commences midnight of the first Saturday night - # following the seven-day festival of Pesach (Passover). The transition - # is from midnight Israel Standard Time to 1 a.m. Israel Daylight Savings - # time. As the Pesach festival is dependent on the Lunar calendar (the - # first day is always on the 15th day of the month of Nisan), the rule - # changes every year on the Gregorian calendar. - # - # 2. Standard Time is reinstated on the Saturday night whereupon Jews - # following the Ashkenazi (European) rite begin to recite the Selichot - # (forgiveness) prayers prior to the Jewish Lunar New Year. The transition - # is from midnight Israel Daylight Savings time to 11 p.m. Israel Standard - # Time. The law (according to the Ashkenazi custom) concerning the - # commencement of the Selichot prayers is described in chapter 128, section - # 5 of the "Code of Jewish Law," by Rabbi Shlomo Ganzfried (translated by - # Hyman E. Goldin): - # - # Beginning with the Sunday [**] before Rosh Hashanah [***], - # we rise early for the service of Selichot (supplications for - # forgiveness). If Rosh Hashanah occurs on Monday or Tuesday, we - # begin saying the Selichot from the Sunday of the preceding week. - # - # This, too, varies from year to year on the Gregorian calendar and, thus, - # two explicit timezone rules are required for each Gregorian year. - # - # [**] actually Saturday night as the Jewish day commences at nightfall. - # [***] the Jewish Lunar New Year. ! # From Paul Eggert (June 16, 1993). Ed Reingold and I converted the above ! # rules into the following Emacs lisp code. It requires GNU Emacs 19.13 ! # or later. If you run the code, the Zion rules will be inserted into ! # your Emacs buffer. Reference: ``Calendrical Calculations'' by Nachum ! # Dershowitz and Edward M. Reingold, Software--Practice and Experience, ! # Volume 20, Number 9 (September, 1990), pages 899-928. # ! # (calendar-for-loop ! # year from 1989 to 2037 do ! # (let ((dst-starts ! # (calendar-gregorian-from-absolute ! # (calendar-dayname-on-or-before ! # 0 ! # (calendar-absolute-from-hebrew ! # (list 1 28 (+ year 3760)))))) ! # (dst-ends ! # (calendar-gregorian-from-absolute ! # (calendar-dayname-on-or-before ! # 0 ! # (- (calendar-absolute-from-hebrew (list 7 1 (+ year 3761))) 3))))) ! # (insert (format "Rule\tZion\t%d\tonly\t-\t%3s\t%2d\t0:00\t1:00\tD\n" ! # year ! # (substring ! # (calendar-month-name (extract-calendar-month dst-starts)) ! # 0 3) ! # (extract-calendar-day dst-starts))) ! # (insert (format "Rule\tZion\t%d\tonly\t-\t%3s\t%2d\t0:00\t0:00\tS\n" ! # year ! # (substring ! # (calendar-month-name (extract-calendar-month dst-ends)) ! # 0 3) ! # (extract-calendar-day dst-ends))))) # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1989 only - Apr 30 0:00 1:00 D ! Rule Zion 1989 only - Sep 24 0:00 0:00 S ! Rule Zion 1990 only - Apr 22 0:00 1:00 D ! Rule Zion 1990 only - Sep 16 0:00 0:00 S ! Rule Zion 1991 only - Apr 7 0:00 1:00 D Rule Zion 1991 only - Sep 1 0:00 0:00 S ! Rule Zion 1992 only - Apr 26 0:00 1:00 D ! Rule Zion 1992 only - Sep 20 0:00 0:00 S ! Rule Zion 1993 only - Apr 18 0:00 1:00 D ! Rule Zion 1993 only - Sep 12 0:00 0:00 S ! Rule Zion 1994 only - Apr 3 0:00 1:00 D ! Rule Zion 1994 only - Aug 28 0:00 0:00 S ! Rule Zion 1995 only - Apr 23 0:00 1:00 D ! Rule Zion 1995 only - Sep 17 0:00 0:00 S ! Rule Zion 1996 only - Apr 14 0:00 1:00 D ! Rule Zion 1996 only - Sep 8 0:00 0:00 S ! Rule Zion 1997 only - May 4 0:00 1:00 D ! Rule Zion 1997 only - Sep 28 0:00 0:00 S ! Rule Zion 1998 only - Apr 19 0:00 1:00 D ! Rule Zion 1998 only - Sep 13 0:00 0:00 S ! Rule Zion 1999 only - Apr 11 0:00 1:00 D ! Rule Zion 1999 only - Sep 5 0:00 0:00 S ! Rule Zion 2000 only - Apr 30 0:00 1:00 D ! Rule Zion 2000 only - Sep 24 0:00 0:00 S ! Rule Zion 2001 only - Apr 15 0:00 1:00 D ! Rule Zion 2001 only - Sep 9 0:00 0:00 S ! Rule Zion 2002 only - Apr 7 0:00 1:00 D ! Rule Zion 2002 only - Sep 1 0:00 0:00 S ! Rule Zion 2003 only - Apr 27 0:00 1:00 D ! Rule Zion 2003 only - Sep 21 0:00 0:00 S ! Rule Zion 2004 only - Apr 18 0:00 1:00 D ! Rule Zion 2004 only - Sep 12 0:00 0:00 S ! Rule Zion 2005 only - May 1 0:00 1:00 D ! Rule Zion 2005 only - Sep 25 0:00 0:00 S ! Rule Zion 2006 only - Apr 23 0:00 1:00 D ! Rule Zion 2006 only - Sep 17 0:00 0:00 S ! Rule Zion 2007 only - Apr 15 0:00 1:00 D ! Rule Zion 2007 only - Sep 9 0:00 0:00 S ! Rule Zion 2008 only - Apr 27 0:00 1:00 D ! Rule Zion 2008 only - Sep 21 0:00 0:00 S ! Rule Zion 2009 only - Apr 19 0:00 1:00 D ! Rule Zion 2009 only - Sep 13 0:00 0:00 S ! Rule Zion 2010 only - Apr 11 0:00 1:00 D ! Rule Zion 2010 only - Sep 5 0:00 0:00 S ! Rule Zion 2011 only - May 1 0:00 1:00 D ! Rule Zion 2011 only - Sep 25 0:00 0:00 S ! Rule Zion 2012 only - Apr 15 0:00 1:00 D ! Rule Zion 2012 only - Sep 9 0:00 0:00 S ! Rule Zion 2013 only - Apr 7 0:00 1:00 D ! Rule Zion 2013 only - Sep 1 0:00 0:00 S ! Rule Zion 2014 only - Apr 27 0:00 1:00 D ! Rule Zion 2014 only - Sep 21 0:00 0:00 S ! Rule Zion 2015 only - Apr 12 0:00 1:00 D ! Rule Zion 2015 only - Sep 6 0:00 0:00 S ! Rule Zion 2016 only - May 1 0:00 1:00 D ! Rule Zion 2016 only - Sep 25 0:00 0:00 S ! Rule Zion 2017 only - Apr 23 0:00 1:00 D ! Rule Zion 2017 only - Sep 17 0:00 0:00 S ! Rule Zion 2018 only - Apr 8 0:00 1:00 D ! Rule Zion 2018 only - Sep 2 0:00 0:00 S ! Rule Zion 2019 only - Apr 28 0:00 1:00 D ! Rule Zion 2019 only - Sep 22 0:00 0:00 S ! Rule Zion 2020 only - Apr 19 0:00 1:00 D ! Rule Zion 2020 only - Sep 13 0:00 0:00 S ! Rule Zion 2021 only - Apr 4 0:00 1:00 D ! Rule Zion 2021 only - Aug 29 0:00 0:00 S ! Rule Zion 2022 only - Apr 24 0:00 1:00 D ! Rule Zion 2022 only - Sep 18 0:00 0:00 S ! Rule Zion 2023 only - Apr 16 0:00 1:00 D ! Rule Zion 2023 only - Sep 10 0:00 0:00 S ! Rule Zion 2024 only - May 5 0:00 1:00 D ! Rule Zion 2024 only - Sep 29 0:00 0:00 S ! Rule Zion 2025 only - Apr 20 0:00 1:00 D ! Rule Zion 2025 only - Sep 14 0:00 0:00 S ! Rule Zion 2026 only - Apr 12 0:00 1:00 D ! Rule Zion 2026 only - Sep 6 0:00 0:00 S ! Rule Zion 2027 only - May 2 0:00 1:00 D ! Rule Zion 2027 only - Sep 26 0:00 0:00 S ! Rule Zion 2028 only - Apr 23 0:00 1:00 D ! Rule Zion 2028 only - Sep 17 0:00 0:00 S ! Rule Zion 2029 only - Apr 8 0:00 1:00 D ! Rule Zion 2029 only - Sep 2 0:00 0:00 S ! Rule Zion 2030 only - Apr 28 0:00 1:00 D ! Rule Zion 2030 only - Sep 22 0:00 0:00 S ! Rule Zion 2031 only - Apr 20 0:00 1:00 D ! Rule Zion 2031 only - Sep 14 0:00 0:00 S ! Rule Zion 2032 only - Apr 4 0:00 1:00 D ! Rule Zion 2032 only - Aug 29 0:00 0:00 S ! Rule Zion 2033 only - Apr 24 0:00 1:00 D ! Rule Zion 2033 only - Sep 18 0:00 0:00 S ! Rule Zion 2034 only - Apr 16 0:00 1:00 D ! Rule Zion 2034 only - Sep 10 0:00 0:00 S ! Rule Zion 2035 only - May 6 0:00 1:00 D ! Rule Zion 2035 only - Sep 30 0:00 0:00 S ! Rule Zion 2036 only - Apr 20 0:00 1:00 D ! Rule Zion 2036 only - Sep 14 0:00 0:00 S ! Rule Zion 2037 only - Apr 12 0:00 1:00 D ! Rule Zion 2037 only - Sep 6 0:00 0:00 S # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] Zone Israel 2:00 Zion I%sT - - # The following is a chart of the day of the week and Gregorian date of - # the first day of Pesach and the first day of Rosh Hashanah for the years - # 1989 through 2009 inclusive. - # - # First Day of Passover - # --------------------- - # Gregorian Year Day of Week Month Day - # -------------- ----------- ----- --- - # 1989 Thursday April 20 - # 1990 Tuesday April 10 - # 1991 Saturday March 30 - # 1992 Saturday April 18 - # 1993 Tuesday April 6 - # 1994 Sunday March 27 - # 1995 Saturday April 15 - # 1996 Thursday April 4 - # 1997 Tuesday April 22 - # 1998 Saturday April 11 - # 1999 Thursday April 1 - # 2000 Thursday April 20 - # 2001 Sunday April 8 - # 2002 Thursday March 28 - # 2003 Thursday April 17 - # 2004 Tuesday April 6 - # 2005 Sunday April 24 - # 2006 Thursday April 13 - # 2007 Tuesday April 3 - # 2008 Sunday April 20 - # 2009 Thursday April 9 - # - # First Day of Rosh Hashanah - # -------------------------- - # Gregorian Year Day of Week Month Day - # -------------- ----------- ----- --- - # 1989 Saturday September 30 - # 1990 Thursday September 20 - # 1991 Monday September 9 - # 1992 Monday September 28 - # 1993 Thursday September 16 - # 1994 Tuesday September 6 - # 1995 Monday September 25 - # 1996 Saturday September 14 - # 1997 Thursday October 2 - # 1998 Monday September 21 - # 1999 Saturday September 11 - # 2000 Saturday September 30 - # 2001 Tuesday September 18 - # 2002 Saturday September 7 - # 2003 Saturday September 27 - # 2004 Thursday September 16 - # 2005 Tuesday October 4 - # 2006 Saturday September 23 - # 2007 Thursday September 13 - # 2008 Tuesday September 30 - # 2009 Saturday September 19 ############################################################################### --- 89,132 ---- # year; as information, regarding exact times and dates during this period, # is not readily available at the present time, the rules commence starting # with the year 1989. ! # From Ephraim Silverberg (September 5, 1993): # ! # According to the Office of the Secretary General of the Ministry of ! # Interior, there is NO set rule for Daylight-Savings/Standard time changes. ! # Each year they decide anew what havoc to wreak on the country. However, ! # there is a "supposed" set of rules which is subject to change depending ! # on the party the Minister of Interior, the size of the coalition ! # government, the phase of the moon and the direction of the wind. Hence, ! # changes may need to be made on a semi-annual basis. One thing is entrenched ! # in law, however: that there must be at least 150 days on daylight savings ! # time annually. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1989 only - Apr 30 0:00 1:00 D ! Rule Zion 1989 only - Sep 3 0:00 0:00 S ! Rule Zion 1990 only - Mar 25 0:00 1:00 D ! Rule Zion 1990 only - Aug 26 0:00 0:00 S ! Rule Zion 1991 only - Mar 24 0:00 1:00 D Rule Zion 1991 only - Sep 1 0:00 0:00 S ! Rule Zion 1992 only - Mar 29 0:00 1:00 D ! Rule Zion 1992 only - Sep 6 0:00 0:00 S ! Rule Zion 1993 only - Apr 2 0:00 1:00 D ! Rule Zion 1993 only - Sep 5 0:00 0:00 S + # The dates for 1994-1995 were obtained from Office of the Spokeswoman for + # the Ministry of Interior, Jerusalem. There are no dates yet for 1996 and + # beyond so your guess is as good as theirs (those who are interested can + # call 972-2-701411 and ask for the spokeswoman). + + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S + Rule Zion 1994 only - Apr 1 0:00 1:00 D + Rule Zion 1994 only - Aug 28 0:00 0:00 S + Rule Zion 1995 only - Mar 31 0:00 1:00 D + Rule Zion 1995 only - Aug 27 0:00 0:00 S + # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] Zone Israel 2:00 Zion I%sT ############################################################################### ----- end of patch ----- From: Ephraim Silverberg <ephraim(a)CS.HUJI.AC.IL> Subject: Re: bugs in entries for Israeli time zones? To: eggert(a)twinsun.com (Paul Eggert) Date: Sun, 5 Sep 93 11:12:02 EET In-Reply-To: <9309022041.AA15967(a)spot.twinsun.com>; from "Paul Eggert" at Sep 2, 93 1:40 pm > The latest version of Arthur David Olson's time zone package claims that > Israel switches from summer time to winter time on September 12. But Yitschak > Goldberg <yits(a)eandm.co.il> writes that it really switches on Sept. 5 this > year. Here is the current entry. Could you tell me what sort of corrections > are needed? I'd like to forward the fixes to Olson (and also to Richard > Stallman, the Emacs author). > > I'm interested in both the historical dates that the time zones changed, and > in the current rules (even if they are likely to change soon). Please don't > feel that you need to make detailed corrections to all this glop! I just > need to know what the current rules are and what the actual transitions > were between 1989 and now. Thanks for any help you can provide. Hi. Appended is the ZIC file with the most current information. Ephraim -------------------------------------------------------------------------------- # Zone Information Compiler (ZIC) File for the State of Israel (1989-2009) # According to the Office of the Secretary General of the Ministry of # Interior, there is NO set rule for Daylight-Savings/Standard time changes. # Each year they decide anew what havoc to wreak on the country. However, # there is a "supposed" set of rules which is subject to change depending # on the party the Minister of Interior, the size of the coalition # government, the phase of the moon and the direction of the wind. Hence, # changes may need to be made on a semi-annual basis. One thing is entrenched # in law, however: that there must be at least 150 days on daylight savings # time annually. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1989 only - Apr 30 0:00 1:00 D Rule Zion 1989 only - Sep 3 0:00 0:00 S Rule Zion 1990 only - Mar 25 0:00 1:00 D Rule Zion 1990 only - Aug 26 0:00 0:00 S Rule Zion 1991 only - Mar 24 0:00 1:00 D Rule Zion 1991 only - Sep 1 0:00 0:00 S Rule Zion 1992 only - Mar 29 0:00 1:00 D Rule Zion 1992 only - Sep 6 0:00 0:00 S Rule Zion 1993 only - Apr 2 0:00 1:00 D Rule Zion 1993 only - Sep 5 0:00 0:00 S # The dates for 1994-1995 were obtained from Office of the Spokeswoman for # the Ministry of Interior, Jerusalem. There are no dates yet for 1996 and # beyond so your guess is as good as theirs (those who are interested can # call 972-2-701411 and ask for the spokeswoman). # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1994 only - Apr 1 0:00 1:00 D Rule Zion 1994 only - Aug 28 0:00 0:00 S Rule Zion 1995 only - Mar 31 0:00 1:00 D Rule Zion 1995 only - Aug 27 0:00 0:00 S # These rules are probably wrong, but they are close approximations (usually # withing two weeks): # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1996 only - Apr 14 0:00 1:00 D Rule Zion 1996 only - Sep 8 0:00 0:00 S Rule Zion 1997 only - May 4 0:00 1:00 D Rule Zion 1997 only - Sep 28 0:00 0:00 S Rule Zion 1998 only - Apr 19 0:00 1:00 D Rule Zion 1998 only - Sep 13 0:00 0:00 S Rule Zion 1999 only - Apr 11 0:00 1:00 D Rule Zion 1999 only - Sep 5 0:00 0:00 S Rule Zion 2000 only - Apr 30 0:00 1:00 D Rule Zion 2000 only - Sep 24 0:00 0:00 S Rule Zion 2001 only - Apr 15 0:00 1:00 D Rule Zion 2001 only - Sep 9 0:00 0:00 S Rule Zion 2002 only - Apr 7 0:00 1:00 D Rule Zion 2002 only - Sep 1 0:00 0:00 S Rule Zion 2003 only - Apr 27 0:00 1:00 D Rule Zion 2003 only - Sep 21 0:00 0:00 S Rule Zion 2004 only - Apr 18 0:00 1:00 D Rule Zion 2004 only - Sep 12 0:00 0:00 S Rule Zion 2005 only - May 1 0:00 1:00 D Rule Zion 2005 only - Sep 25 0:00 0:00 S Rule Zion 2006 only - Apr 23 0:00 1:00 D Rule Zion 2006 only - Sep 17 0:00 0:00 S Rule Zion 2007 only - Apr 15 0:00 1:00 D Rule Zion 2007 only - Sep 9 0:00 0:00 S Rule Zion 2008 only - Apr 27 0:00 1:00 D Rule Zion 2008 only - Sep 21 0:00 0:00 S Rule Zion 2009 only - Apr 19 0:00 1:00 D Rule Zion 2009 only - Sep 13 0:00 0:00 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Israel 2:00 Zion I%sT

1 0

Re: Kwajalein bug fix
by ado Aug. 28, 1993

Aug. 28, 1993

Thanks to Paul Eggert for the Kwajalein changes. My notions on how to do it are attached. It might be better to toss Kwajalein into australasia than to create a new file; as I recall, some vendors might be using a "patch" scheme that's better at handling changes than handling additions. I also took the opportunity while visiting zdump to eliminate the "VERY approximate" kludge in handling zdump's "-c" option. (Given the relentless increase in processor power, maybe the better thing to do is eliminate the "-c" option.) I'll wait a bit for feedback from this list; eventually folks should expect to see tzcode93e.tar.Z and tzdata93e.tar.Z on elsie.nci.nih.gov. --ado SCCS/s.australasia: 7.13 vs. 7.14 *** 7.13/australasia Sat Aug 28 12:29:52 1993 --- 7.14/australasia Sat Aug 28 12:29:52 1993 *************** *** 1,4 **** ! # @(#)australasia 7.13 # Notes are at the end of this file --- 1,4 ---- ! # @(#)australasia 7.14 # Notes are at the end of this file *************** *** 105,110 **** --- 105,118 ---- ############################################################################### + # Kwajalein + + # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] + Zone Kwajalein -12:00 - KST 1993 Aug 20 + 12:00 - KST + + ############################################################################### + # NOTES ############################################################################### *************** *** 431,433 **** --- 439,451 ---- # From Arthur David Olson (March 8, 1992): # The chosen rules use the Davies October 8 values for the start of DST in 1989 # rather than the October 1 value. + + ############################################################################### + + # Kwajalein + + # In comp.risks 14.87 (26 August 1993), Peter Neumann writes: + # I wonder what happened in Kwajalein, where there was NO Friday, + # August 20, 1993. Thursday night at midnight Kwajalein switched sides with + # respect to the International Date Line, to rejoin its fellow islands, + # going from 11:59 p.m. Thursday to 12:00 m. Saturday in a blink. SCCS/s.zdump.c: 7.3 vs. 7.5 *** 7.3/zdump.c Sat Aug 28 12:30:03 1993 --- 7.5/zdump.c Sat Aug 28 12:30:03 1993 *************** *** 1,6 **** #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)zdump.c 7.3"; #endif /* !defined NOID */ #endif /* !defined lint */ --- 1,6 ---- #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)zdump.c 7.5"; #endif /* !defined NOID */ #endif /* !defined lint */ *************** *** 39,46 **** #define SECSPERMIN 60 #endif /* !defined SECSPERMIN */ #ifndef SECSPERHOUR ! #define SECSPERHOUR 3600 #endif /* !defined SECSPERHOUR */ #ifndef HOURSPERDAY --- 39,50 ---- #define SECSPERMIN 60 #endif /* !defined SECSPERMIN */ + #ifndef MINSPERHOUR + #define MINSPERHOUR 60 + #endif /* !defined MINSPERHOUR */ + #ifndef SECSPERHOUR ! #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) #endif /* !defined SECSPERHOUR */ #ifndef HOURSPERDAY *************** *** 51,60 **** --- 55,72 ---- #define EPOCH_YEAR 1970 #endif /* !defined EPOCH_YEAR */ + #ifndef TM_YEAR_BASE + #define TM_YEAR_BASE 1900 + #endif /* !defined TM_YEAR_BASE */ + #ifndef DAYSPERNYEAR #define DAYSPERNYEAR 365 #endif /* !defined DAYSPERNYEAR */ + #ifndef isleap + #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) + #endif /* !defined isleap */ + extern char ** environ; extern int getopt(); extern char * optarg; *************** *** 104,116 **** argv[0], argv[0]); (void) exit(EXIT_FAILURE); } ! if (cutoff != NULL) cutyear = atoi(cutoff); ! /* ! ** VERY approximate. ! */ ! cuttime = (long) (cutyear - EPOCH_YEAR) * ! SECSPERHOUR * HOURSPERDAY * DAYSPERNYEAR; (void) time(&now); longest = 0; for (i = optind; i < argc; ++i) --- 116,130 ---- argv[0], argv[0]); (void) exit(EXIT_FAILURE); } ! if (cutoff != NULL) { ! int y; ! cutyear = atoi(cutoff); ! cuttime = 0; ! for (y = EPOCH_YEAR; y < cutyear; ++y) ! cuttime += DAYSPERNYEAR + isleap(y); ! cuttime *= SECSPERHOUR * HOURSPERDAY; ! } (void) time(&now); longest = 0; for (i = optind; i < argc; ++i) *************** *** 231,243 **** struct tm * oldp; { long result; ! result = newp->tm_hour - oldp->tm_hour; ! if (result < 0) ! result += HOURSPERDAY; ! result *= SECSPERHOUR; ! result += (newp->tm_min - oldp->tm_min) * SECSPERMIN; ! return result + newp->tm_sec - oldp->tm_sec; } static void --- 245,265 ---- struct tm * oldp; { long result; + int tmy; ! if (newp->tm_year < oldp->tm_year) ! return -delta(oldp, newp); ! result = 0; ! for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) ! result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE); ! result += newp->tm_yday - oldp->tm_yday; ! result *= HOURSPERDAY; ! result += newp->tm_hour - oldp->tm_hour; ! result *= MINSPERHOUR; ! result += newp->tm_min - oldp->tm_min; ! result *= SECSPERMIN; ! result += newp->tm_sec - oldp->tm_sec; ! return result; } static void

1 0

Kwajalein bug fix
by eggert＠stet.twinsun.com Aug. 26, 1993

Aug. 26, 1993

Kwajalein's missing day uncovered a bug in zdump.c, which missed the 24-hour jump ahead because the jump was masked by the HOURSPERDAY hack in the `delta' function. Here's a patch, plus a proposed new `pacific' file for islands in the Pacific. I've made up the abbreviation `KST'; I don't know what abbreviation Kwajaleinians really use. I don't know when Kwajalein originally started using -12:00 -- it must have been soon after WW II. *** /dev/null Fri Aug 27 07:48:01 1993 --- pacific Fri Aug 27 07:38:41 1993 *************** *** 0 **** --- 1,14 ---- + # @(#)pacific + + + # Kwajalein + + # In comp.risks 14.87 (26 August 1993), Peter Neumann writes: + # I wonder what happened in Kwajalein, where there was NO Friday, + # August 20, 1993. Thursday night at midnight Kwajalein switched sides with + # respect to the International Date Line, to rejoin its fellow islands, + # going from 11:59 p.m. Thursday to 12:00 m. Saturday in a blink. + + # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] + Zone Kwajalein -12:00 - KST 1993 Aug 20 + 12:00 - KST =================================================================== RCS file: zdump.c,v retrieving revision 7.3 retrieving revision 7.3.1.1 diff -c -r7.3 -r7.3.1.1 *** zdump.c 1993/01/08 12:00:38 7.3 --- zdump.c 1993/08/26 21:08:10 7.3.1.1 *************** *** 55,60 **** --- 55,64 ---- #define DAYSPERNYEAR 365 #endif /* !defined DAYSPERNYEAR */ + #ifndef TM_YEAR_BASE + #define TM_YEAR_BASE 1900 + #endif + extern char ** environ; extern int getopt(); extern char * optarg; *************** *** 230,243 **** struct tm * newp; struct tm * oldp; { ! long result; ! ! result = newp->tm_hour - oldp->tm_hour; ! if (result < 0) ! result += HOURSPERDAY; ! result *= SECSPERHOUR; ! result += (newp->tm_min - oldp->tm_min) * SECSPERMIN; ! return result + newp->tm_sec - oldp->tm_sec; } static void --- 234,256 ---- struct tm * newp; struct tm * oldp; { ! int newy = newp->tm_year + (TM_YEAR_BASE - 1); ! int oldy = oldp->tm_year + (TM_YEAR_BASE - 1); ! return ! ( ! ( ! ( ! /* difference in day of year */ ! newp->tm_yday - oldp->tm_yday ! /* + intervening leap days */ ! + (newy/4 - oldy/4) ! - (newy/100 - oldy/100) ! + (newy/400 - oldy/400) ! /* + difference in years * 365 */ ! + (long)(newy-oldy) * 365 ! )*24 + (newp->tm_hour - oldp->tm_hour) ! )*60 + (newp->tm_min - oldp->tm_min) ! )*60 + (newp->tm_sec - oldp->tm_sec); } static void

1 0

Item forwarded from comp.protocols.time.ntp
by ado Aug. 26, 1993

Aug. 26, 1993

> From bob(a)kahala.soest.hawaii.edu Mon Aug 23 17:07:53 1993 > Path: nih-csl!darwin.sura.net!howland.reston.ans.net!agate!ames!news.Hawaii.Edu!kahala!bob > From: bob(a)kahala.soest.hawaii.edu (Bob Cunningham) > Newsgroups: comp.protocols.time.ntp > Subject: time trivia, Kwajelein skips a day > Message-ID: <CC8DD5.7It(a)news.Hawaii.Edu> > Date: 23 Aug 93 21:07:53 GMT > Sender: news(a)news.Hawaii.Edu > Organization: School of Ocean and Earth Science and Technology > Lines: 18 > Originator: bob@kahala > > Everyone living on the remote Pacific atoll of Kwajelein in the > Marshall Islands will have a good excuse for not remembering last > Saturdy night. There wasn't one. Residents went to bed on Friday and > woke up on Sunday. There was no 21st of August. The government just > changed Kwajelein to Marshallese time, effectively jumping the island > from one side of the International Date Line to the far side (where it > actually is, the IDL being 300 miles to east of Kwaj). The US Army has > for the last 40 years been synchronizing the day of the week for its > workers on Kwaj with the US mainland. > > But most workers didn't lose a day off. The work week was shifted to > Tuesday through Saturday, corresponding with Monday through Friday on > the mainland. > > -- > Bob Cunningham > bob(a)soest.hawaii.edu > School of Ocean & Earth Science & Technology, University of Hawaii

1 0

Is leap second support working in the latest time zone code?
by eggert＠twinsun.com July 9, 1993

July 9, 1993

With the latest time zone code I tried `zdump -v right/US/Pacific' and got the following output. This looks wrong to me -- the times labeled `GMT' are actually International Atomic Time (TAI), not Coordinated Universal Time (UTC). zdump uses gmtime to print the GMT part. But even with leap second support, gmtime should yield UTC, not TAI, at least according to ANSI C X3.159-1989 section 4.12.3.3. Or am I missing something here? right/US/Pacific Sun Apr 4 10:00:16 1993 GMT = Sun Apr 4 01:59:59 1993 PST isdst=0 right/US/Pacific Sun Apr 4 10:00:17 1993 GMT = Sun Apr 4 03:00:00 1993 PDT isdst=1 right/US/Pacific Thu Jul 1 00:00:17 1993 GMT = Wed Jun 30 16:59:60 1993 PDT isdst=1 right/US/Pacific Thu Jul 1 00:00:18 1993 GMT = Wed Jun 30 17:00:00 1993 PDT isdst=1 right/US/Pacific Sun Oct 31 09:00:17 1993 GMT = Sun Oct 31 01:59:59 1993 PDT isdst=1 right/US/Pacific Sun Oct 31 09:00:18 1993 GMT = Sun Oct 31 01:00:00 1993 PST isdst=0

2 1

Solaris 2.2 has many timezone bugs
by eggert＠shadow.twinsun.com June 22, 1993

June 22, 1993

Solaris 2.2 seems based on a particularly ancient version of the timezone code. It has many bugs that, near as I can tell, were fixed as long ago as 1989 in the public domain version. This is a real step backwards from SunOS 4.1.x. The most serious bug will occur on October 24, 1993 in GB-Eire: Solaris 2.2's switch from summer to winter time will be delayed until October 31. There are some other bugs in Australia, Brazil, Chile, Israel, and Korea zones. I just filed an official bug report with Sun, but I don't have much hope of it having an effect in time. Perhaps someone with some influence at Sun can get them to upgrade to the latest tz code before Solaris 2.3 comes out. Or I could just post a note to comp.risks...

1 0

Julian date conversion code
by jim＠bilbo.suite.com June 19, 1993

June 19, 1993

Does anyone know where I can find some public domain code that converts Julian (and Modified Julian) Dates to "seconds since start of (UNIX/GMT)" and back? thanks, Jim-Miller(a)suite.com

1 0

Re: tz93c botches time zone transitions in Brazil
by ado June 18, 1993

June 18, 1993

Thanks for this new fix. Both it and the new data on Israel are now incorporated in ~ftp/pub/tzcode93d.tar.Z and ~ftp/pub/tzdata93d.tar.Z on elsie.nci.nih.gov (128.231.16.1). (And I think the woes of elsie's transition from being a Sun 3 to being a Sun 4 are over.) --ado

1 0

tz93c botches time zone transitions in Brazil
by eggert＠twinsun.com June 18, 1993

June 18, 1993

Ed Reingold noticed that SunOS 4.1.2 mishandles the time zone transitions in Brazil. Typically, it claims that the transitions occur on Friday, whereas the rule says they should occur on Saturday. The bug is still present in tz93c (the 1993-06-06 version of the time zone code). I looked into the problem, and discovered that zic botches any rule whose ON field is of the form `DAY<=N', where DAY is not Sunday, and where the Nth day of the current year is not DAY. In this case, it acts as if you specified the previous day to DAY. As it happens, the only rules of this form in the database are those of Brazil. For example if you run `zdump -v Brazil/East' you'll see that most of the transitions occur on Friday, but they're all supposed to occur on Saturday. Here is a patch to tz93c. I'm amazed that this bug has never been reported in all these years. Shall we chalk it up to Brazil's strict import restrictions on American software? =================================================================== RCS file: zic.c,v retrieving revision 7.8 retrieving revision 7.8.1.1 diff -c -r7.8 -r7.8.1.1 *** zic.c 1993/06/06 23:31:38 7.8 --- zic.c 1993/06/18 02:58:46 7.8.1.1 *************** *** 1819,1825 **** } else { dayoff = oadd(dayoff, (long) -1); if (--wday < 0) ! wday = LDAYSPERWEEK; --i; } if (i < 0 || i >= len_months[isleap(y)][m]) { --- 1819,1825 ---- } else { dayoff = oadd(dayoff, (long) -1); if (--wday < 0) ! wday = LDAYSPERWEEK - 1; --i; } if (i < 0 || i >= len_months[isleap(y)][m]) {

1 0

automated generation of the Zion rules
by eggert＠twinsun.com June 17, 1993

June 17, 1993

Here's a patch to the Zion rules that gives a program to generate the rules, plus the DST transitions for the years 2010 through 2037. =================================================================== RCS file: asia,v retrieving revision 1.1 retrieving revision 1.2 diff -c -r1.1 -r1.2 *** asia 1992/04/23 17:34:49 1.1 --- asia 1993/06/17 00:04:53 1.2 *************** *** 119,124 **** --- 119,157 ---- # [**] actually Saturday night as the Jewish day commences at nightfall. # [***] the Jewish Lunar New Year. + # From Paul Eggert (June 16, 1993). Ed Reingold and I converted the above + # rules into the following Emacs lisp code. It requires GNU Emacs 19.13 + # or later. If you run the code, the Zion rules will be inserted into + # your Emacs buffer. Reference: ``Calendrical Calculations'' by Nachum + # Dershowitz and Edward M. Reingold, Software--Practice and Experience, + # Volume 20, Number 9 (September, 1990), pages 899-928. + # + # (calendar-for-loop + # year from 1989 to 2037 do + # (let ((dst-starts + # (calendar-gregorian-from-absolute + # (calendar-dayname-on-or-before + # 0 + # (calendar-absolute-from-hebrew + # (list 1 28 (+ year 3760)))))) + # (dst-ends + # (calendar-gregorian-from-absolute + # (calendar-dayname-on-or-before + # 0 + # (- (calendar-absolute-from-hebrew (list 7 1 (+ year 3761))) 3))))) + # (insert (format "Rule\tZion\t%d\tonly\t-\t%3s\t%2d\t0:00\t1:00\tD\n" + # year + # (substring + # (calendar-month-name (extract-calendar-month dst-starts)) + # 0 3) + # (extract-calendar-day dst-starts))) + # (insert (format "Rule\tZion\t%d\tonly\t-\t%3s\t%2d\t0:00\t0:00\tS\n" + # year + # (substring + # (calendar-month-name (extract-calendar-month dst-ends)) + # 0 3) + # (extract-calendar-day dst-ends))))) + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 1989 only - Apr 30 0:00 1:00 D Rule Zion 1989 only - Sep 24 0:00 0:00 S *************** *** 162,167 **** --- 195,256 ---- Rule Zion 2008 only - Sep 21 0:00 0:00 S Rule Zion 2009 only - Apr 19 0:00 1:00 D Rule Zion 2009 only - Sep 13 0:00 0:00 S + Rule Zion 2010 only - Apr 11 0:00 1:00 D + Rule Zion 2010 only - Sep 5 0:00 0:00 S + Rule Zion 2011 only - May 1 0:00 1:00 D + Rule Zion 2011 only - Sep 25 0:00 0:00 S + Rule Zion 2012 only - Apr 15 0:00 1:00 D + Rule Zion 2012 only - Sep 9 0:00 0:00 S + Rule Zion 2013 only - Apr 7 0:00 1:00 D + Rule Zion 2013 only - Sep 1 0:00 0:00 S + Rule Zion 2014 only - Apr 27 0:00 1:00 D + Rule Zion 2014 only - Sep 21 0:00 0:00 S + Rule Zion 2015 only - Apr 12 0:00 1:00 D + Rule Zion 2015 only - Sep 6 0:00 0:00 S + Rule Zion 2016 only - May 1 0:00 1:00 D + Rule Zion 2016 only - Sep 25 0:00 0:00 S + Rule Zion 2017 only - Apr 23 0:00 1:00 D + Rule Zion 2017 only - Sep 17 0:00 0:00 S + Rule Zion 2018 only - Apr 8 0:00 1:00 D + Rule Zion 2018 only - Sep 2 0:00 0:00 S + Rule Zion 2019 only - Apr 28 0:00 1:00 D + Rule Zion 2019 only - Sep 22 0:00 0:00 S + Rule Zion 2020 only - Apr 19 0:00 1:00 D + Rule Zion 2020 only - Sep 13 0:00 0:00 S + Rule Zion 2021 only - Apr 4 0:00 1:00 D + Rule Zion 2021 only - Aug 29 0:00 0:00 S + Rule Zion 2022 only - Apr 24 0:00 1:00 D + Rule Zion 2022 only - Sep 18 0:00 0:00 S + Rule Zion 2023 only - Apr 16 0:00 1:00 D + Rule Zion 2023 only - Sep 10 0:00 0:00 S + Rule Zion 2024 only - May 5 0:00 1:00 D + Rule Zion 2024 only - Sep 29 0:00 0:00 S + Rule Zion 2025 only - Apr 20 0:00 1:00 D + Rule Zion 2025 only - Sep 14 0:00 0:00 S + Rule Zion 2026 only - Apr 12 0:00 1:00 D + Rule Zion 2026 only - Sep 6 0:00 0:00 S + Rule Zion 2027 only - May 2 0:00 1:00 D + Rule Zion 2027 only - Sep 26 0:00 0:00 S + Rule Zion 2028 only - Apr 23 0:00 1:00 D + Rule Zion 2028 only - Sep 17 0:00 0:00 S + Rule Zion 2029 only - Apr 8 0:00 1:00 D + Rule Zion 2029 only - Sep 2 0:00 0:00 S + Rule Zion 2030 only - Apr 28 0:00 1:00 D + Rule Zion 2030 only - Sep 22 0:00 0:00 S + Rule Zion 2031 only - Apr 20 0:00 1:00 D + Rule Zion 2031 only - Sep 14 0:00 0:00 S + Rule Zion 2032 only - Apr 4 0:00 1:00 D + Rule Zion 2032 only - Aug 29 0:00 0:00 S + Rule Zion 2033 only - Apr 24 0:00 1:00 D + Rule Zion 2033 only - Sep 18 0:00 0:00 S + Rule Zion 2034 only - Apr 16 0:00 1:00 D + Rule Zion 2034 only - Sep 10 0:00 0:00 S + Rule Zion 2035 only - May 6 0:00 1:00 D + Rule Zion 2035 only - Sep 30 0:00 0:00 S + Rule Zion 2036 only - Apr 20 0:00 1:00 D + Rule Zion 2036 only - Sep 14 0:00 0:00 S + Rule Zion 2037 only - Apr 12 0:00 1:00 D + Rule Zion 2037 only - Sep 6 0:00 0:00 S # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] Zone Israel 2:00 Zion I%sT

1 0

time zone survey
by ado June 11, 1993

June 11, 1993

Attached are results from a casual time zone survey. Last week I ran through the news articles on nih-csl.dcrt.nih.gov (the nntp newsfeed system for elsie.nci.nih.gov) getting the "Date: " and "Message-ID: " line from each article. Article file names were obtained from the news history file to ensure that any cross-posted articles would only be used once. I tossed out data with unzoned time stamps, data without a recognizable domained system name in the Message-ID, and data from ".com" sites. This left 17,912 date/name pairs. I massaged the data into the form... 05210205 (AEST) megalink.apana.org.au 05010053 +0000 compex.e-burg.su ...where the first field gives two digits each of month, day, hour, and minute from the Date, the second field gives the time zone that appeared in the Date, and the third field is the system name from the Message-ID. This data is available in the file ~ftp/pub/zonesurvey on elsie.nci.nih.gov (128.231.16.1). Eighty-nine different zones showed up (sorted alphabetically here): (AEST) +0000 +0001 +0100 +02 +0200 +0300 +0400 +0500 +0530 +0600 +0611 +0700 +0730 +0800 +0930 +1 +1000 +1100 +1200 +1300 +1700 -0000 -0100 -0300 -0400 -0500 -0520 -0600 -0700 -0800 -1 -1000 -1200 -600 ACST ADT AEST AET ARG AST BSC BST CDT CED CEST CET CST DST EDT EDZ EET EMT EST GMT GMT+01 GMT+0200 GMT+1 GMT+12 GMT+1200 GMT+2 IDT IST JST LCL MDT MED MES MEST MESZ MET MEWT MEZ MST NDT NZDT NZST PDT PST SGP TUR TZONE U UT WET WET+0100 WST XDT Y The number of times each zone showed up (sorted by number of times here): 3820 -0400 1925 EDT 1902 -0500 994 EST 919 -0700 913 CDT 748 +0000 690 +0200 664 CST 655 PDT 621 +0100 583 -0600 499 +1000 467 MDT 398 PST 275 +1200 211 BST 170 +0001 153 MET 138 -0800 135 MST 123 +0300 116 CET 98 +0800 97 -0300 53 +0400 51 +0930 45 -0100 36 +1300 35 WET 33 -0000 27 UT 23 ACST 22 MEZ 22 NZST 20 +1700 20 GMT+12 17 IDT 16 TUR 14 MESZ 9 +02 8 MEST 8 WET+0100 7 +0600 7 CED 7 CEST 7 LCL 6 AET 6 DST 6 EET 6 EMT 5 AST 5 GMT 5 GMT+01 5 GMT+0200 5 U 4 -1000 4 IST 3 +0700 3 +1100 3 -0520 3 -1200 3 -600 3 EDZ 3 TZONE 3 Y 2 ADT 2 ARG 2 BSC 2 GMT+1200 2 MED 2 MES 2 SGP 1 (AEST) 1 +0500 1 +0530 1 +0611 1 +0730 1 +1 1 -1 1 AEST 1 GMT+1 1 GMT+2 1 JST 1 MEWT 1 NDT 1 NZDT 1 WST 1 XDT Aside from the 51 "+0930" articles from Australia, only four "oddball" numeric time zones show up, and each of them only shows up from one system (the Date and system name from the original data are shown here): 3 -0520 Wed, 2 Jun 93 22:22:00 -0520 freddy.ampr.ab.ca Thu, 3 Jun 93 20:08:00 -0520 freddy.ampr.ab.ca Sat, 5 Jun 93 16:05:00 -0520 freddy.ampr.ab.ca 1 +0530 1 Jun 93 15:30:55 +0530 imtech.ernet.in 1 +0611 Wed, 02 Jun 93 16:08:33 +0611 trashcan.hacktic.nl 1 +0730 6 Jun 1993 08:25:56 +0730 news.Colorado.EDU Time zone abbrevations that show up in tzdata93c.tar.Z files: ADT Atlantic Daylight Time AST Atlantic Standard Time BST British Standard Time CDT Central Daylight Time CET Central European Time CST Central Standard Time EDT Eastern Daylight Time EET Eastern European Time EST Eastern Standard Time IDT Israeli Daylight Time IST Israeli Standard Time JST Japanese Standard Time MDT Mountain Daylight Time MET Middle European Time MST Mountain Standard Time NZDT New Zealand Daylight Time NZST New Zealand Standard Time PDT Pacific Daylight Time PST Pacific Standard Time WET Western European Time WST Western Standard Time Time zone abbreviations that are fairly clear are: (AEST) Australian Eastern Standard Time (used only by one system) Fri, 21 May 93 02:05:36 (AEST) megalink.apana.org.au ACST Australian Central Standard Time 21 May 93 13:18:16 ACST state.systems.sa.gov.au Tue, 25 May 93 13:27:42 ACST cola.pax.tpa.com.au ... 4 Jun 93 00:47:42 ACST state.systems.sa.gov.au Sun, 06 Jun 93 19:13:17 ACST cola.pax.tpa.com.au AEST Australian Eastern Standard Time Fri, 04 Jun 93 21:47:10 AEST ese.escape.brisnet.org.au AET Australian Eastern Time (used only by one system) 10 May 93 08:50:04 AET licre.ludwig.edu.au 27 May 93 19:00:11 AET licre.ludwig.edu.au 28 May 93 12:46:13 AET licre.ludwig.edu.au 1 Jun 93 08:46:51 AET licre.ludwig.edu.au 1 Jun 93 09:02:16 AET licre.ludwig.edu.au 7 Jun 93 14:52:39 AET licre.ludwig.edu.au CED Central European Daylight 28 Apr 93 21:00:06 CED alphanet.alphanet.ch 27 May 93 22:53:59 CED sourcery.han.de 28 May 93 18:36:06 CED sourcery.han.de 1 Jun 93 22:16:54 CED sourcery.han.de 1 Jun 93 22:22:52 CED sourcery.han.de 1 Jun 93 22:45:24 CED sourcery.han.de 2 Jun 93 21:05:10 CED sourcery.han.de CEST Central European Standard Time Tue, 25 May 93 07:26:34 CEST obula.nbg.sub.org Tue, 25 May 93 15:58:02 CEST obula.nbg.sub.org Wed, 26 May 93 12:46:27 CEST obula.nbg.sub.org Tue, 01 Jun 93 11:18:35 CEST obula.nbg.sub.org Wed, 02 Jun 93 08:42:25 CEST obula.nbg.sub.org Fri, 04 Jun 1993 17:45:26 CEST oktagon.rd.sub.org Sun, 06 Jun 93 20:44:27 CEST scrum.greenie.muc.de MED Middle European Daylight (used only by one system) 3 Jun 93 00:17:24 MED lifestyle.rhein-main.de 6 Jun 93 12:27:48 MED lifestyle.rhein-main.de MES Middle European Standard (used only by one system) Sat, 22 May 93 12:46:44 MES wolferts.ka.sub.org Sun, 06 Jun 93 15:05:50 MES wolferts.ka.sub.org MESZ Middle European Standard Zone Tue, 25 May 1993 17:49:06 MESZ email.tuwien.ac.at Wed, 26 May 1993 12:12:26 MESZ gwdu14.gwdg.de Wed, 26 May 93 14:03:58 MESZ lbl.gov Fri, 28 May 1993 00:02:42 MESZ nasim.sta.sub.org Fri, 28 May 1993 00:03:34 MESZ nasim.sta.sub.org Fri, 28 May 1993 00:04:26 MESZ nasim.sta.sub.org Fri, 28 May 1993 00:12:50 MESZ nasim.sta.sub.org Fri, 28 May 1993 00:13:56 MESZ nasim.sta.sub.org Fri, 28 May 1993 00:15:10 MESZ nasim.sta.sub.org Sat, 29 May 1993 01:30:40 MESZ nasim.sta.sub.org Tue, 01 Jun 1993 00:46:06 MESZ nasim.sta.sub.org Thu, 03 Jun 93 10:48:04 MESZ aie.wu-wien.ac.at Fri, 4 Jun 93 10:56:33 MESZ exaib.wu-wien.ac.at Fri, 4 Jun 93 11:06:41 MESZ exaib.wu-wien.ac.at MEST Middle European Standard Time Tue, 25 May 93 12:45:47 MEST xivic.bo.open.de Tue, 25 May 93 14:20:53 MEST xivic.bo.open.de Tue, 25 May 93 14:48:22 MEST xivic.bo.open.de Wed, 26 May 93 23:22:22 MEST joker.wes.open.de Sat, 29 May 1993 18:22:55 MEST netmbx.netmbx.de Sat, 29 May 1993 18:21:07 MEST netmbx.netmbx.de Sun, 30 May 1993 12:57:21 MEST netmbx.netmbx.de Tue, 1 Jun 1993 21:51:09 MEST netmbx.netmbx.de MEZ Middle European Zone (used primarily in Germany) Mon, 10 May 93 20:47:50 MEZ rhrz.uni-bonn.de Wed, 26 May 93 12:59:57 MEZ vm.univie.ac.at ... Sun, 06 Jun 1993 14:32:28 MEZ sartar.toppoint.de Sun, 06 Jun 1993 18:37:50 MEZ sartar.toppoint.de UT Universal Time (used only by one system) 29 May 1993 21:14 UT kelvin.jpl.nasa.gov 31 May 1993 15:40 UT kelvin.jpl.nasa.gov ... 3 Jun 1993 21:36 UT kelvin.jpl.nasa.gov 4 Jun 1993 00:20 UT kelvin.jpl.nasa.gov WET+0100 Western European Time+0100 8 Apr 93 15:00:02 WET+0100 ittpub.nl 1 Jun 93 19:26:08 WET+0100 ittpub.nl 2 Jun 93 16:17:13 WET+0100 ittpub.nl 2 Jun 93 20:24:36 WET+0100 ittpub.nl 4 Jun 93 13:32:33 WET+0100 ittpub.nl 4 Jun 93 13:39:50 WET+0100 ittpub.nl 4 Jun 93 13:47:53 WET+0100 ittpub.nl 4 Jun 93 14:08:22 WET+0100 ittpub.nl Time zone abbreviations that are guesswork are: ARG Argentina? Tue, 25 May 93 12:46:21 ARG satlink.net Thu, 27 May 93 07:36:01 ARG satlink.net BSC ? Tue, 25 May 1993 10:51:05 BSC FINHUTC.HUT.FI Tue, 1 Jun 1993 11:57:00 BSC brfapesp.bitnet DST Daylight Saving Time? Thu, 27 May 93 11:00:24 DST cmrra.ca Thu, 27 May 93 23:31:02 DST cmrra.ca Fri, 28 May 93 17:26:14 DST cmrra.ca Sat, 29 May 93 16:48:42 DST cmrra.ca Sat, 29 May 93 16:54:30 DST cmrra.ca Sun, 30 May 93 14:38:30 DST cmrra.ca EDZ ? Mon, 31 May 93 18:14:42 EDZ wship.nullnet.fi Fri, 04 Jun 93 20:41:41 EDZ swob.nullnet.fi Fri, 04 Jun 93 20:53:45 EDZ swob.nullnet.fi EMT ? 28 Apr 1993 12:08:23 EMT alf.uib.no 29 Apr 1993 11:15:44 EMT alf.uib.no 29 Apr 1993 11:17:15 EMT alf.uib.no 28 May 1993 17:56:54 EMT alf.uib.no 1 Jun 1993 19:43:42 EMT alf.uib.no 3 Jun 1993 18:09:42 EMT alf.uib.no MEWT ? 12 May 93 07:41:03 MEWT mble.philips.be LCL LoCaL time? Tue, 1 Jun 1993 09:18:43 LCL kona.cc.mcgill.ca Wed, 2 Jun 1993 07:48:00 LCL mp.cs.niu.edu Wed, 2 Jun 1993 13:44:00 LCL mp.cs.niu.edu Thu, 3 Jun 1993 09:33:00 LCL oas2-tic.safb.af.mil Thu, 3 Jun 1993 08:25:39 LCL grouse.umesve.maine.edu Fri, 4 Jun 1993 20:09:05 LCL CUVMB.COLUMBIA.EDU Fri, 4 Jun 1993 20:19:59 LCL CUVMB.COLUMBIA.EDU NDT ? Tue, 25 May 1993 15:39:29 NDT UBVM.CC.BUFFALO.EDU SGP ? Mon, 31 May 93 15:43:36 SGP uwm.edu Fri, 4 Jun 93 10:20:26 SGP uwm.edu TUR Turkey? Wednesday, 5 May 1993 23:23:11 TUR TRMETU.BITNET Wednesday, 26 May 1993 09:03:58 TUR TRMETU.BITNET Wednesday, 26 May 1993 09:05:39 TUR TRMETU.BITNET Wednesday, 26 May 1993 09:06:26 TUR TRMETU.BITNET Wednesday, 26 May 1993 20:47:38 TUR TRMETU.BITNET Thursday, 27 May 1993 10:15:14 TUR TRMETU.BITNET Thursday, 27 May 1993 12:28:59 TUR TREARN.BITNET Thursday, 27 May 1993 13:20:19 TUR TRMETU.BITNET Thursday, 27 May 1993 15:20:12 TUR TRMETU.BITNET Friday, 28 May 1993 11:01:42 TUR TREARN.BITNET Friday, 28 May 1993 12:53:52 TUR TRMETU.BITNET Sunday, 30 May 1993 12:15:24 TUR TREARN.BITNET Saturday, 29 May 1993 12:46:01 TUR TRMETU.BITNET Monday, 31 May 1993 21:44:49 TUR TRMETU.BITNET Saturday, 5 Jun 1993 18:30:45 TUR TREARN.BITNET Sunday, 6 Jun 1993 13:14:56 TUR TREARN.BITNET TZONE ? Mon, 31 May 1993 05:01:19 TZONE VAXF.COLORADO.EDU Wed, 2 Jun 1993 19:59:49 TZONE carson.u.washington.edu Fri, 4 Jun 1993 09:21:33 TZONE sunburn.uwaterloo.ca XDT ? Tue, 25 May 1993 10:20:55 XDT sfanet.nrl.navy.mil The results make me think there's little prospect of discovering useful time zone information (in particular, time transitions that don't already show up in tzdata93c.tar.Z) from running through news articles; someone with an account on a site that does extensive archiving of news might prove me wrong. --ado

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Re: time zone survey
by guy＠auspex.com June 11, 1993

June 11, 1993

> (Yes, in SysV the file has to be changed every > year again. And SGI shows no inclination to change.) Actually, I think SVR4 includes the Olson code, although I don't think all SVR4.0 systems supply the Olson files. However, I infer from one of Eric Raymond's lists of SVR4 bugs that SVR4.2 does supply the Olson files *and* uses Olson-style timezone specifications (":" followed by the time zone file name) by default. (The bug was that SVR4.0 binaries allegedly don't work with SVR4.2 time zone names, an example of which was given as "US/Eastern" or something such as that; that seems a *tad* bizarre, as if SVR4.0 has the Olson code, SVR4.0 statically-linked binaries should be able to handle Olson-style names, and SVR4.0 dynamically-linked binaries should use SVR4.2 shared libraries and should thus also be able to handle them. Perhaps the bug was that SVR3.x binaries don't handle Olson-style names.) SVR4 uses "/etc/TIMEZONE", but you can set TZ to ":MET" and you shouldn't have to change it every year. (Also, SVR4 should also support POSIX-style TZ settings, which should allow you to put in a value that doesn't require periodic updates *if* your locale's DST rules are sufficiently "regular" that they can be encoded in the TZ setting. I don't know which SVR3.x systems, if any, supported that.) If, as, and when IRIX goes to an SVR4 base, they should probably pick up the Olson code with it.

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Re: time zone survey
by Dik.Winter＠cwi.nl June 11, 1993

June 11, 1993

> Attached are results from a casual time zone survey. An interesting survey. > I tossed out data with unzoned time stamps, data without a recognizable > domained system name in the Message-ID, and data from ".com" sites. Why did you toss out data from ".com" sites? > 1 +0530 > 1 Jun 93 15:30:55 +0530 imtech.ernet.in This might be a valid one. It is apparently from India which lives around +5 and +6. > 1 +0611 > Wed, 02 Jun 93 16:08:33 +0611 trashcan.hacktic.nl This one is definitely invalid. Most probably a PC hooked up to hacktic (a public access system in the Netherlands). Probably the owner did set it up wrong. > 1 +0730 > 6 Jun 1993 08:25:56 +0730 news.Colorado.EDU Ha! If even Colorado.Edu cannot get it correct! ;-). > MESZ Middle European Standard Zone Probably "Mittel Europ"aische Standard Zeit". > MEZ Middle European Zone (used primarily in Germany) "Mittel Europ"aische Zeit". And yes, primarily german speaking countries. > BSC ? > Tue, 25 May 1993 10:51:05 BSC FINHUTC.HUT.FI > Tue, 1 Jun 1993 11:57:00 BSC brfapesp.bitnet These two are definitely not in the same timezone. One is in Finland, one in Brazil. > TUR Turkey? Probably yes. All sites are in Turkey. > The results make me think there's little prospect of discovering useful > time zone information (in particular, time transitions that don't already > show up in tzdata93c.tar.Z) from running through news articles; someone > with an account on a site that does extensive archiving of news might prove > me wrong. I think there is no prospect at all. And it will grow worse. In the case of the "hacktic.nl" machine we see that we have a single machine that is configured wrong. I think more of this kind of machines will emerge. They do not care what time the system runs on, as long as it is internally consistent (and even that is not needed at all times). Time transitions especially will be a problem, and it will continue to be a problem. At our institute during the transition to DST all Suns (which use your package) switched on time, but all SGI's (using SysV's method) did not. The system administrator simply had forgotten to update the file that contained timezone information (/etc/TIMEZONE) and it took a few days before somebody noticed. (Yes, in SysV the file has to be changed every year again. And SGI shows no inclination to change.) So I think nobody will prove you wrong.

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Re: "32 time zones"
by Amos Shapir June 9, 1993

June 9, 1993

> I don't know about any zones with > three-quarter hour offsets, but would like to know what they are. >From the same usno1989 file (which is outdated and contains errors, but seems to be the most comprehensive source we have): NEPAL 5H45M AHEAD OF UTC NEW ZEALAND 12H45M AHEAD OF UTC CHATHAM ISLAND In the Rand-McNally atlas there are a few other Pacific islands with 40 mins offsets, all of which appear as full or half-hour zones in the file; it also lists Nepal at GMT+5:40 and Liberia as -0:44 (yes, forty four) -- makes sense since Monrovia is at exactly 11 degrees west, but probably outdated too. Amos Shapir Net: amos(a)cs.huji.ac.il Paper: The Hebrew Univ. of Jerusalem, Dept. of Comp. Science. Givat-Ram, Jerusalem 91904, Israel Tel: +972 2 585706 GEO: 35 11 46 E / 31 46 21 N

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"32 time zones"
by ado June 8, 1993

June 8, 1993

Our society has created a fictional time system of 32 time zones (24 one-hour offsets and several more half-hour and three-quarter hour offsets). --Tognazzini, Bruce (tog(a)eng.sun.com) "Tog on Interface: The Myth of Precision", Sun World, volume 6, number 7 (June, 1993), page 100. A grep in /usr/lib/zoneinfo/* on a SunOS 4.1.1 system failed to show up eight oddball time zones (see attached). Does anyone know of the origin for the "32" time zones? --ado

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Re: "32 time zones"
by tog＠cloud9.Eng.Sun.COM June 8, 1993

June 8, 1993

Well, so much for my books are better than computers theory. Still and all, I can think of no atlas that would manage to tell one person there were 24 zones and another person there were 40 zones. We have a long way to go not only in information storage, but in responsive retrieval. -Tog > From amos(a)cs.huji.ac.il Tue Jun 8 07:02:26 1993 > To: ado(a)bossie.nci.nih.gov (Arthur David Olson) > Subject: Re: "32 time zones" > Cc: tog@Eng, tz(a)bossie.nci.nih.gov > Content-Length: 579 > X-Lines: 13 > > Well, you didn't grep hard enough; I just did: > > grep '[.H][0-9]' /usr/share/lib/zoneinfo/usno1989 > > And got 11 part-hour zones, 3 of which apply DST which can be also counted as > separate timezones; plus Russia's East Siberia zone which is 13 hours ahead of > GMT and 14 with DST. In total, we have 24+12+4 or 40 time zones, 36 of which > are in use somewhere at any given time. > > Amos Shapir Net: amos(a)cs.huji.ac.il > Paper: The Hebrew Univ. of Jerusalem, Dept. of Comp. Science. > Givat-Ram, Jerusalem 91904, Israel > Tel: +972 2 585706 GEO: 35 11 46 E / 31 46 21 N >

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Re: "32 time zones"
by tog＠cloud9.Eng.Sun.COM June 8, 1993

June 8, 1993

Try any (printed) atlas. Or wait until the next century when computers just barely begin to catch up with where printed matter was 300 years ago. Grepping indeed! -Tog > From ado(a)bossie.nci.nih.gov Tue Jun 8 06:40:56 1993 > To: amos(a)cs.huji.ac.il, tog@Eng, tz(a)bossie.nci.nih.gov > Subject: "32 time zones" > Content-Length: 481 > X-Lines: 13 > > Our society has created a fictional time system of 32 time zones > (24 one-hour offsets and several more half-hour and three-quarter > hour offsets). > > --Tognazzini, Bruce (tog(a)eng.sun.com) "Tog on Interface: > The Myth of Precision", Sun World, volume 6, number 7 > (June, 1993), page 100. > > A grep in /usr/lib/zoneinfo/* on a SunOS 4.1.1 system failed to show up eight > oddball time zones (see attached). Does anyone know of the origin for the > "32" time zones? > > --ado >

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Re: "32 time zones"
by Amos Shapir June 8, 1993

June 8, 1993

Well, you didn't grep hard enough; I just did: grep '[.H][0-9]' /usr/share/lib/zoneinfo/usno1989 And got 11 part-hour zones, 3 of which apply DST which can be also counted as separate timezones; plus Russia's East Siberia zone which is 13 hours ahead of GMT and 14 with DST. In total, we have 24+12+4 or 40 time zones, 36 of which are in use somewhere at any given time. Amos Shapir Net: amos(a)cs.huji.ac.il Paper: The Hebrew Univ. of Jerusalem, Dept. of Comp. Science. Givat-Ram, Jerusalem 91904, Israel Tel: +972 2 585706 GEO: 35 11 46 E / 31 46 21 N

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tzcode93c.tar.Z and tzdata93c.tar.Z
by ado June 6, 1993

June 6, 1993

The latest versions of the time zone stuff are available in the files tzcode93c.tar.Z and tzdata93c.tar.Z in the ~ftp/pub directory on elsie.nci.nih.gov (128.231.16.1). --ado

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