Date: Fri, 04 Oct 1996 19:34:39 -0500 (EST) From: Gwillim Law 919-852-4294 <LAW@encmail.encompass.com> I thought the tz mailing list would want to see these changes, and compare them to those reported by other sources. That is a very helpful contribution; thanks. I compared the IATA changes with the changes reported by other tz contributors, and have the following comments. Later, I'll send out a draft patch reflecting these comments, as well as all the other comments received so far. * Armenia stopped using DST this year, according to Edgar Der-Danieliantz <edd@AIC.NET> (1996-05-04). Did the IATA catch this change? * Azerbaijan data from the IATA disagrees with both Shanks and USNO. I guess that the IATA is right, and that we're missing some transitions between 1991 and 1996. Azerbaijan apparently enjoys the distinction of being the first Asian country to use the European Union's DST rules (including switching at 0100 UTC). * Brazil - You wrote: three states (Alagoas, Sergipe, and Tocantins) will begin using DST, probably on October 13, 1996. Could you give more details about this? The entries that you sent made it look like only the DST dates were adjusted. As far as I can tell from other sources, DST is observed uniformly in Brazil, even in the far north where the hemisphere is wrong. Perhaps these states used to be 2 hours behind UTC, and are now 3? This would agree with the map in <URL:http://www.bancobrasil.com.br/bbtur.ing/bbttime.htm>, but so far I've discounted that map, not only because no other sources have UTC-2 Brazilian mainland, but also because its line between UTC-2 and UTC-3 is suspiciously straight. Also, some of the beginning and end dates for DST were adjusted by a week. You gave the change only for BR1; were the dates also changed for other zones in Brazil? It would be odd if the different parts of Brazil had different DST dates. All the Brazilian transitions that we know of since 1989 are consistent with the rules Oct Sun>=10 00:00 and Feb Sun>=10 00:00; I'll propose a change to the tz rules accordingly. * Iran The tz database had Iran not using DST since 1980. For lack of better info I'll assume they readopted DST in 1996. Iran now apparently moves its clocks approximately on the equinoxes -- I think it's the only country to do this. * Kazakhstan - you wrote: Kazakhstan, formerly unified on UTC+6 with DST, will divide into three zones. They will observe UTC+4, 5, and 6, all with DST. The western zone (UTC+4) consists of Aktau, Atyrau, and Uralsk oblasts, and the central zone is Aktyubinsk oblast. Andrew Evtichov <evti@chevron.com> (1996-04-13) wrote that Kazakhstan has had multiple time zones for quite some time: at least 2 ``always'' and 3 now. I'd guess that the IATA SSIM is just catching up with this fact. Unfortunately, I misparsed his earlier message and thought that Kazakhstan had just 2 time zones now; he actually wrote that it has 3. I'll add a new zone for Aqtobe (formerly Aktyubinsk) and rename Asia/Aktau to Asia/Aqtau since `Aqtau' name seems to be the usual English rendering of the Kazakh name. * Lebanon. Lebanon returned from DST to Standard Time on September 28, 1996, instead of October 26 as previously announced. Shanks has Lebanon switching on May 1 and Oct 16 every year. Evidently that has changed more than once since 1991. For lack of better info I'll propose a patch so that Lebanon switches on the last Sunday in March and the last Sunday in September, starting 1996. * Libya if I'm right, the first actual time change was on September 30, 1996, when clocks were set back an hour. That sounds right: since 1959, Libya has switched back and forth between straight UTC+2 and UTC+1 with DST. * Mexico - the IATA and tz agree. * Mongolia The IATA says that changes occur at local midnight, whereas Shanks says they occur at 02:00 standard time. Also, the IATA says the fall transition is the 4th Friday (!) in October, whereas tz said it was the last Sunday in September. I'll assume that the IATA is right, and that the rules changed in 1996, but we're undoubtedly missing some other changes between 1985 and 1995. * Paraguay Paraguay will return from DST to Standard Time on March 1, 1997, instead of February 23 as previously announced. Shanks has this transition occuring on April 1. For lack of better info, I'll assume they changed the rules from April 1 to March 1 in 1996. * Portugal Portugal (excluding Azores and Madeira) has switched from UTC+1 to UTC (both using DST). There's no indication of when the change occurred. Martin Bruckmann <martin@ua.pt> (1996-02-29) reported that the change occurred this spring, by Portugal not changing its clocks. * Russia Russia's fall transition used to be the last Sunday in September, but it's changed to the last Sunday in October (at 02:00 standard time, as before). Did the IATA catch this change? Presumably this change also applies to Kazakhstan (I just checked the ricc.kz time server in Alma-Ata, and they're still on DST) as well as Kirgizstan. While we're on the subject, in the absence of any better info, the current tz database assumes that Belarus, Estonia, Latvia, Lithuania, and Moldova are moving their clocks on the last Sunday in October at 02:00 standard time, starting this year (in previous years they used September). Since the EU, Russia, and Ukraine are all known to be making a similar switch, it wouldn't be surprising if the other countries are switching too; but we have no info. * Sri Lanka Sri Lanka has changed from UTC+5:30 to UTC+6:30 year-round. There's no indication of when the change occurred. It occurred 1996-05-25 00:00 local time, according to LankaWeb <URL:http://www.virtual-pc.com/lankaweb/news/items/240596-2.html>. * Ukraine Ukraine will begin and end DST at 3:00 am local time, rather than midnight as it used to. (The data make it clear that this is 3:00 local standard time.) For most of Ukraine, this makes sense, since it's the EU rules. However, for Crimea, it doesn't make sense, since it's neither the EU rules (which operate at 4:00 local standard time) nor the Moscow rules (which operate at 2:00 local standard time). Apparently the Ukrainians and the Crimeans are having a little tussle; there was a news story about this by Itar-Tass <URL:http://www.itar-tass.com/tassnews.htm> at 09-18 00:43 entitled ``Crimea ponders over problem of time zone'' but unfortunately I don't have a copy of the story. For now I'll assume Crimea was using Moscow rules until this year, and is as IATA reports afterwards. Shanks says all of Ukraine switches at 2:00 standard time, not midnight. For lack of better info I'll assume that this was true through 1995.