- tz - lists.iana.org

FW: FW: Corrections to historic German timezone information
by Olson, Arthur David (NIH/NCI) [E] Feb. 11, 2008

Feb. 11, 2008

I'm forwarding this message from Sebastian Wangnick, who is not on the time zone mailing list (at least not at the address below). Those of you who are on the time zone mailing list should direct replies appropriately. --ado -----Original Message----- From: Sebastian Wangnick [mailto:sebastian.nospam01@wangnick.de] Sent: Monday, February 04, 2008 5:09 To: tz(a)lecserver.nci.nih.gov Subject: WG: FW: Corrections to historic German timezone information Dear all, it seems the email below did not reach the mailing list. Kind regards, Sebastian Wangnick -----Ursprüngliche Nachricht----- Von: Sebastian Wangnick [mailto:sebastian.nospam01@wangnick.de] Gesendet: Dienstag, 29. Januar 2008 19:18 An: 'Paul Eggert' Cc: 'tz(a)elsie.nci.nih.gov' Betreff: AW: FW: Corrections to historic German timezone information Dear Paul, I understand your concern. As proposed, the timezone Europe/Berlin would be applicable for the "western" countries of the state of Germany and the western part of Berlin, and Europe/BerlinEast for what was formerly first the Sowjet zone and later the state GDR, namely the "eastern" countries of the state of Germany (Mecklenburg-Vorpommern, Brandenburg, Sachsen, Sachsen-Anhalt, Thüringen) and the eastern part of Berlin. Creation of individual timezones for each of the countries of Germany is thus unneccessary. http://de.wikipedia.org/wiki/Bild:Deutschland_politisch_bunt.png However, if you can maintain only one timezone for the state of Germany, you should probably use the new definition of Europe/Berlin, limiting the error in 1945 to the smaller territory and population, but please note that this would be considered politically incorrect by said population. In this case we will privately maintain a modified copy of the tz database. Kind regards, Sebastian Wangnick

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when did China adopt one time zone?
by Paul Eggert Feb. 8, 2008

Feb. 8, 2008

In a book review in today's issue of _Science_ you reported that the Chinese government in 1949 opted to observe one time zone. This caught my interest because I help maintain the tz database, which records histories of time zone and daylight saving changes all over the world. The tz database is used by computer clocks all over the world, including what I expect are millions of clocks in China, so I'd like to get the details right. Here's the problem: the tz database, following Shanks & Pottenger (2003), records that the China switched to a single time zone on May 1, 1980, not in 1949. Since you are a historian of China I expect that you have a lot better sources than we do. Can you please mention the sources for the claim that the clocks changed in 1949 rather than in 1980? Thanks for any info you can provide. I'll CC: this message to the tz database mailing list, to give them a heads-up on this query. -- Paul Eggert, UCLA Computer Science Dept. References: Thomas S. Mullaney, Change of time over changing time. Science 319 (5864), 729 (2008-02-08), DOI: 10.1126/science.1152851, <http://www.sciencemag.org/cgi/content/full/319/5864/729a>. Paul Eggert & Arthur David Olson, Sources for time zone and daylight saving time data <http://www.twinsun.com/tz/tz-link.htm> (2007-12-31); also see <http://en.wikipedia.org/wiki/Zoneinfo>. Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition). San Diego: ACS Publications, Inc. (2003).

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WG: FW: Corrections to historic German timezone information
by Sebastian Wangnick Feb. 4, 2008

Feb. 4, 2008

Dear all, it seems the email below did not reach the mailing list. Kind regards, Sebastian Wangnick -----Ursprüngliche Nachricht----- Von: Sebastian Wangnick [mailto:sebastian.nospam01@wangnick.de] Gesendet: Dienstag, 29. Januar 2008 19:18 An: 'Paul Eggert' Cc: 'tz(a)elsie.nci.nih.gov' Betreff: AW: FW: Corrections to historic German timezone information Dear Paul, I understand your concern. As proposed, the timezone Europe/Berlin would be applicable for the "western" countries of the state of Germany and the western part of Berlin, and Europe/BerlinEast for what was formerly first the Sowjet zone and later the state GDR, namely the "eastern" countries of the state of Germany (Mecklenburg-Vorpommern, Brandenburg, Sachsen, Sachsen-Anhalt, Thüringen) and the eastern part of Berlin. Creation of individual timezones for each of the countries of Germany is thus unneccessary. http://de.wikipedia.org/wiki/Bild:Deutschland_politisch_bunt.png However, if you can maintain only one timezone for the state of Germany, you should probably use the new definition of Europe/Berlin, limiting the error in 1945 to the smaller territory and population, but please note that this would be considered politically incorrect by said population. In this case we will privately maintain a modified copy of the tz database. Kind regards, Sebastian Wangnick

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Re: FW: Corrections to historic German timezone information
by Paul Schauble Feb. 4, 2008

Feb. 4, 2008

It might be easier to acknowledge the west/east Berlin split than to figure out which single rule is better. The problem I see is that in reality the presnt day Berlin and the historic Berlin did not exist for 40 years. I am not sure this can be ignored. ++PLS ----- Original Message ----- From: Markus Scherer <markus.icu(a)gmail.com> To: tz(a)lecserver.nci.nih.gov <tz(a)lecserver.nci.nih.gov> Cc: Sebastian Wangnick <sebastian.nospam01(a)wangnick.de>; tz(a)lecserver.nci.nih.gov <tz(a)lecserver.nci.nih.gov> Sent: Sun Feb 03 15:58:24 2008 Subject: Re: FW: Corrections to historic German timezone information On Jan 28, 2008 3:59 PM, Paul Eggert <eggert(a)cs.ucla.edu> wrote: > Because of this rule, the 1945 divergence doesn't justify having two > separate entries for Berlin. However, we should have the correct > entry for Berlin, which raises the question: where is the commonly > accepted center of Berlin? If the center is in the former Soviet > zone, tz's Europe/Berlin should use what is in the proposed > Europe/BerlinEast zone. If Berlin's center is in the former > west-Berlin zone, Europe/Berlin should change to match what is in the > proposed Europe/Berlin zone. I don't quite understand this. I do understand that it's overkill from the perspective of the TZ maintainers to precisely distinguish pre-1970 transitions, but it seems like the question of which part of Berlin to use should not depend as much on where the city center is but on the political continuity. markus -- Opinions expressed here may not reflect my company's positions unless otherwise noted.

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FW: Corrections to historic German timezone information
by Olson, Arthur David (NIH/NCI) [E] Feb. 3, 2008

Feb. 3, 2008

I'm forwarding this message from Sebastian Wangnick, who is not on the time zone mailing list. Those of you who are on the time zone mailing list should direct replies appropriately. --ado From: Sebastian Wangnick [mailto:sebastian.nospam01@wangnick.de] Sent: Sunday, January 27, 2008 2:02 To: tz(a)lecserver.nci.nih.gov Cc: time(a)ptb.de Subject: Corrections to historic German timezone information Dear Madam, dear Sir, I understand that the historic time zone database you maintain is the basis of calendar computations in many computer systems and programming languages, including Linux and Tcl. We are using said data in some of our applications. Many thanks for your effort. Please find attached a few modifications to your tz2007k data files, so as to bring them in line with the publications of the Arbeitsgruppe 4.41 of the Physikalisch-Technische Bundesanstalt at http://www.ptb.de/de/org/4/44/441/salt.htm. The mistake in tz2007k is that the special 1945 rules for East Berlin and the German Sowjet Zone mentioned in bullet point c) of the website above are applied to Germany in general. The modifications return Europe/Berlin to the standard rules a) and b), and introduce a new zone Europe/BerlinEast where a), b) and c) are applied. Cc to the PTB for information. Kind regards, Sebastian Wangnick -- Sebastian Wangnick Lammersdorfer Str. 61 D-52159 Roetgen/Rott

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Fw: GUATEMALA from DST 30 APR to 29 SEP 2008
by Gwillim Law Feb. 3, 2008

Feb. 3, 2008

Risto Nykänen wrote me that Guatemala is going to observe DST from 2008-04-30 to 2008-09-29. Searching for confirmation, I found an article at http://www.prensalibre.com/pl/2008/enero/29/217165.html, apparently from a Guatemalan newspaper. It says: "El Gobierno guatemalteco adelantará la hora oficial en a partir del 30 de abril en un intento por reducir la demanda de energía eléctrica. "'Ya es un hecho, se va a cambiar a finales de abril para tener horario de verano', dijo el vocero presidencial Fernando Barillas. "Con la medida el ejecutivo espera obtener un ahorro de 60 megavatios diarios entre el 30 de abril y el 30 de septiembre, cuando termine el horario especial. ..." My translation: "The Guatemalan government will advance official time starting on April 30 in an initiative to reduce demand for electrical energy. "'It is already a done deed, we are going to change at the end of April to observe summer time', the presidential spokesman Fernando Barillas said. "With this measure the executive hopes to save 60 megawatts a day between April 30 and September 30, when the special schedule ends." Gwillim Law

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Another developer writing code to use the tz database
by Goudge, Stephen Jan. 28, 2008

Jan. 28, 2008

Hello, I'd like to express my gratitude and admiration to all the contributors to the time zone database. I am working to make use of the tzdata* information to attach timezone data plus a UTC timestamp to video recordings made by a DVR and to then, during playback, display the correct local time to match the video irrespective of the timezone settings on the playback computer. To fit the needs of the DVR, instead of storing an id string we have to store (at most) a 16-bit integer, so there is a C enum plus lookup table to map from these integer 'tz codes' to string ids that can be matched against the names in the tzdata files. So obviously there is an immediate maintenance need to keep the enum and mapping in step with tzdata - and this has an interesting correspondence to the declared needs of the CLDR project in terms of the stability of the tz id strings... For various reasons, including the need for playback to operate under Windows and to fit the new functionality into an existing code base, I opted to modify 'zic' and all the time functions (localtime etc). The time functions are changed to remove the limitations of the Posix approach (setting a global TZ, formatting one time value, resetting the global TZ...) and to convert the representation from time_t to the one we use internally (effectively Windows FILETIME as a 64-bit value); the results have then been attached to the C++ 'time' classes we use. 'zic' was then modified to change the epoch etc to match FILETIME and then, as I really didn't want to dump a load of settings into the Registry nor create a raft of files to tempt our Users to fiddle, write out a single Zip archive with the compiled tz data. Both of these items - the C library containing the enum and the C++ library with modified 'zic' etc - are Open Source, although I haven't "published" them on any websites or repositories (well, not recently enough to contain these TZ related tweaks). I would welcome any interest in seeing this code, if only to give the impetus to tidy it up well enough to "publish" (although, a warning, this is "Yet Another Pile of Someone's Favourite Stuff" and the TZ materials are currently fairly well integrated into the middle of it all). Regards, Stephen Goudge Transport R&D Petards Joyce-Loebl Gateshead, UK Private, Confidential and Privileged. This e-mail and any files and attachments transmitted with it are confidential and/or privileged. They are intended solely for the use of the intended recipient(s). The content of this e-mail and any file or attachment transmitted with it may have been changed or altered without the consent of the author. If you are not the intended recipient, please note that any review, dissemination, disclosure, alteration, printing, circulation or transmission of this e-mail and/or any file or attachment transmitted with it, is prohibited and may be unlawful. If you have received this e-mail or any file or attachment transmitted with it in error please notify the IT Manager, Petards Joyce-Loebl Limited, 390 Princesway, Gateshead, NE11 0TU, telephone no: +44 191 4203000. Petards Joyce-Loebl Limited is registered in England under number 2170100 DISCLAIMER: Privileged / Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my company shall be understood as neither given nor endorsed by it. _____________________________________________________________________________________ This email has been scanned by Petards Joyce-Loebl. The service is powered by MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email. _____________________________________________________________________________________

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about San Luis, Argentina, timezone changes
by Mariano Absatz Jan. 28, 2008

Jan. 28, 2008

Hi people, I'm sorry for being silent so far... I've been on Holidays (it's plain summer down here, kinda like August up there)... in fact, the first days of 2008 I've been in the Province of San Luis (but before the announcement of San Luis going back to UTC-3). I just arrived from the second part of my vacation (in the Province of Buenos Aires) a few hours ago, and I've been completely off-line (otherwise, it wouldn't actually be a vacation :-) ) I can confirm that the Province of San Luis (and so far only that province) decided to go back to UTC-3 effective midnight Jan 20th 2008 (that is, Monday 21st at 0:00 is the time the clocks were delayed back 1 hour), and they intend to keep UTC-3 as their timezone all year round (that is, unless they change their mind any minute now). I can't see the official San Luis website since their DNS servers are quite silent today (in fact they seem not be routeable today from 3 different places) :-( So we'll have to add yet another city to 'southamerica' (I think San Luis city is the mos populated city in the Province, so it'd be America/Argentina/San_Luis... of course I can't remember if San Luis's history of particular changes goes along with Mendoza or San Juan :-( (I only remember not being able to collect hard facts about San Luis back in 2004, when these provinces changed to UTC-4 for a few days, I mailed them personally and never got an answer). As for the origin of the problem, it has many faces: * *Political:* If the Governor of a Province is somehow /against/ the National Government, then, it's Province is more likely to diverge from the National Government timezone proposal. * *Geographical:* As you can see in http://aa.usno.navy.mil/faq/docs/world_tzones.php Most of Argentina is geographically in UTC-4. NONE of it is in UTC-3. A small part of the SouthWest is actually in UTC-5 (like Chile). The current UTC-3 is originated in a DST mostly used between 1930 and 1969 (UTC-4 was the "official" timezone at that time) that "never went back" after being turned "on" in 1969-10-05... after that, it was kinda "renamed" to official (non-DST) time and at some point, UTC-2 was started to be used as DST (in 1974 and then between 1988 and 1993 and some other years after that). The West-most Provinces (Mendoza, San Juan, San Luis, Neuquen, Catamarca, etc.) started a crusade in 2004 to re-install UTC-4 as the standard (winter) time and UTC-3 as the DST, but they failed in disorder (and thus generated some chaos in tzdata) * *Cultural:* Part of the problem is originated in our culture... as of the end of the 20th Century and beginning of the 21st, most of Argentine people is *very* used to dinner at *night*... that is, you can't call it *dinner* if there's daylight... most of start having dinner somewhere between 9PM and 10PM or later... if Argentina uses UTC-2 in the summer (when the daylight lasts longer), the more to the West and to the South you go, the later daylight goes off... The first week of January 2008, using UTC-2, I've been in the NorthEast of San Luis and the daylight disappeared after 10PM, so everybody went to dinner at about 10:30PM or later, so, instead of saving electricity, most people used the same or more electricity than before the change. My parents just came back from El Calafate (in the SouthWest of the Province of Santa Cruz) and they told me daylight was going off at about 11:30 PM. Another cultural problem is that Argentina, although being a federal country (at least in the papers), which somehow gives some autonomy to the Provinces, is not used to have more than one timezone (as the USA is), and, like western Europe, works better within one timezone... the struggle is about which timezone it is... Regards. -- Mariano Absatz - "El Baby" baby(a)baby.com.ar -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Lottery: A tax on people who are bad at math. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- * TagZilla 0.066 * http://tagzilla.mozdev.org

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Corrections to historic German timezone information
by Sebastian Wangnick Jan. 27, 2008

Jan. 27, 2008

Dear Madam, dear Sir, I understand that the historic time zone database you maintain is the basis of calendar computations in many computer systems and programming languages, including Linux and Tcl. We are using said data in some of our applications. Many thanks for your effort. Please find attached a few modifications to your tz2007k data files, so as to bring them in line with the publications of the Arbeitsgruppe 4.41 of the Physikalisch-Technische Bundesanstalt at http://www.ptb.de/de/org/4/44/441/salt.htm. The mistake in tz2007k is that the special 1945 rules for East Berlin and the German Sowjet Zone mentioned in bullet point c) of the website above are applied to Germany in general. The modifications return Europe/Berlin to the standard rules a) and b), and introduce a new zone Europe/BerlinEast where a), b) and c) are applied. Cc to the PTB for information. Kind regards, Sebastian Wangnick -- Sebastian Wangnick Lammersdorfer Str. 61 D-52159 Roetgen/Rott

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San Luis time change
by Jesper Norgaard Welen Jan. 26, 2008

Jan. 26, 2008

Unfortunately the below page has become defunct, about the San Luis time change. Perhaps because it now is part of a group of pages "Most important pages of 2008". You can use http://www.sanluis.gov.ar/notas.asp?idCanal=8141&id=22834 instead it seems. Or use "Buscador" from the main page of the San Luis government, and fill in "huso" and click OK, and you will get 3 pages from which the first one is identical to the above. - Jesper -----Original Message----- From: Jesper Norgaard Welen [mailto:jnorgard@prodigy.net.mx] Sent: Viernes, 18 de Enero de 2008 22:57 To: tz(a)lecserver.nci.nih.gov Subject: San Luis time change this Monday The page of the San Luis provincial government http://www.sanluis.gov.ar/notas.asp?idCanal=0&id=22812 confirms ...

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