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Timezones in international waters
by Oscar van Vlijmen March 21, 2005

March 21, 2005

An update to the discussion about timezones at sea, discussed around 2000-01-05 (see tzarchive). The mentioned date I posted a list, with corrections by Gwillim Law. Recently I found a more or less official reference: Bowditch - The American Practical Navigator, Chapter 18 Time, Section 1806 Zone Time; National Imagery And Mapping Agency; 1995. More information, a table, an algorithm, a web link to Bowditch: see my Multizones web page: <http://home-4.tiscali.nl/~t876506/Multizones.html#iw> See also "The International Date Line" at the end of the TZ australasia file. Oscar van Vlijmen 2005-03-20

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Daylight Savings Time in Kazakhstan?!
by Stefan Hellwig March 17, 2005

March 17, 2005

Hi, I just subscribed to this list so please bear with me if this issue has been discussed already or does not fit in here... This week I was informed that the government of Kazakhstan has decided NOT to perform the "time switch" from winter to summer time anymore (it was mentioned in a local newspaper). Does anyone know if this is really the case and if there is a timezone definition file for that already? The current rule set for the Kazakh timezone Asia/Almaty says: [...] Rule RussiaAsia 1996 max - Oct lastSun 2:00s 0 - [...] Zone Asia/Almaty 5:07:48 - LMT 1924 May 2 # or Alma-Ata 5:00 - ALMT 1930 Jun 21 # Alma-Ata Time 6:00 RussiaAsia ALM%sT 1991 6:00 - ALMT 1992 6:00 RussiaAsia ALM%sT So right now it's scheduled for March 27 (lastSun) at 2:00am. If they don't do that switch anymore we'd have to change that timezone definition on our servers there... Can anyone confirm this "rumor"? Thanks & Regards, Stefan.

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Change in local time in Uruguay
by Eduardo Cota March 15, 2005

March 15, 2005

There has been a change in local time in Uruguay. The decree (dated 10 March 2005) can be found here. http://www.presidencia.gub.uy/_Web/decretos/2005/03/cm%205.PDF Basically it says that the summer time this year is extended until 27/3/2005, at 2:00. We changed our local zones (on a FreeBSD box) for the file southamerica in the following way: 1060c1060 < Rule Uruguay 2005 only - Mar Sun>=8 0:00 0 - --- > Rule Uruguay 2005 only - Mar 27 2:00 0 - Yours, Eduardo Cota.

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RE: Is more detailed timezone history desired?
by Olson, Arthur David (NIH/NCI) March 14, 2005

March 14, 2005

One possibility would be to take advantage of the name space; zic input such as... Zone Past/America/East-Podunk ... ...would segregate data for now-inactive time zones; this would make the data available without unduly cluttering the main directory and subdirectories. --ado

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Tzcode2005g.tar.gz and tzdata2005g.tar.gz
by Olson, Arthur David (NIH/NCI) March 14, 2005

March 14, 2005

The files... ftp://elsie.nci.nih.gov/pub/tzcode2005g.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2005g.tar.gz ...are now available; these reflect the changes circulated on the time zone mailing list last week by Paul Eggert (a change to current DST rules in Uruguay and an update to a link to time zone software). --ado

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Two more weeks with DST in Uruguay
by Steffen Thorsen March 12, 2005

March 12, 2005

Uruguay's DST was scheduled to end on Sunday, 2005-03-13, but in order to save energy; it was postponed two weeks, until 2005-03-27, at either 3 or 2 in the morning (I'm not quite sure because the automatic translation tools don't give a very good translation). The official announcement is available here (Spanish): http://www.presidencia.gub.uy/_Web/noticias/2005/03/2005031005.htm Some background information is available here (also Spanish): http://www.cncs.com.uy/?tc=nt&nt=2543 Best regards, Steffen

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FW: Who ist the maintainer of tzdata?
by Olson, Arthur David (NIH/NCI) March 12, 2005

March 12, 2005

Since sending this message Alois Treindl has joined the time zone mailing list. --ado -----Original Message----- From: Alois Treindl [mailto:alois@astro.ch] Sent: Thursday, March 10, 2005 5:24 AM To: tz(a)lecserver.nci.nih.gov Subject: Who ist the maintainer of tzdata? I have a project to expand tzdata. Summarizing shortly, the rough idea is to - add boundary descriptions to each area with a different timezone history so that with given coordinates it can automatically be determined to which timezone history 'table' a given location belongs. I am aware that many non-trivial issues of geo-information processing arise with such a goal. - add more details for the complicated timezone history of some countries, e.g. Canada, where other sources have identified more than 250 regions with different timezone history, whereas current tzdata has only 15 regions. I am aware that this is a large project which will require resources measured in man-years. I may be in a position to contribute/sponsor such resources. I would like to communicate with the current maintainers of tzdata about these ideas, and about the best approach for such an expansion. My motivation background is the field of serious astrology, where reliable timezone history information is an essential requirement. tzdata is doing an excellent job to provide reliable information for current timzones, but it lacks sadly (and understandably, given the complexity of the problem) in historical detail. Alois Treindl

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proposed tz change for Uruguay (plus tz-link update)
by Paul Eggert March 11, 2005

March 11, 2005

Here's a proposed change to the tz database to reflect the news from Uruguay. The tz rules for Uruguay are currently incorrect for time stamps past this Sunday. Thanks to Steffen Thorsen for the info about Uruguay. Also, this patch adds a link to VelaTerra's recent offer of free licenses to tz database contributors. =================================================================== RCS file: RCS/southamerica,v retrieving revision 2005.5 retrieving revision 2005.5.0.2 diff -pu -r2005.5 -r2005.5.0.2 --- southamerica 2005/02/07 21:19:42 2005.5 +++ southamerica 2005/03/11 23:31:13 2005.5.0.2 @@ -1063,8 +1063,12 @@ Rule Uruguay 1993 only - Feb 28 0:00 0 # From Eduardo Cota (2004-09-20): # The uruguayan government has decreed a change in the local time.... # http://www.presidencia.gub.uy/decretos/2004091502.htm -Rule Uruguay 2004 only - Sep Sun>=15 0:00 1:00 S -Rule Uruguay 2005 only - Mar Sun>=8 0:00 0 - +Rule Uruguay 2004 only - Sep 19 0:00 1:00 S +# From Steffen Thorsen (2005-03-11): +# Uruguay's DST was scheduled to end on Sunday, 2005-03-13, but in order to +# save energy ... it was postponed two weeks.... +# http://www.presidencia.gub.uy/_Web/noticias/2005/03/2005031005.htm +Rule Uruguay 2005 only - Mar 27 2:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Montevideo -3:44:44 - LMT 1898 Jun 28 -3:44:44 - MMT 1920 May 1 # Montevideo MT =================================================================== RCS file: RCS/tz-link.htm,v retrieving revision 2005.6 retrieving revision 2005.6.0.2 diff -pu -r2005.6 -r2005.6.0.2 --- tz-link.htm 2005/03/01 13:44:11 2005.6 +++ tz-link.htm 2005/03/11 23:35:28 2005.6.0.2 @@ -9,7 +9,7 @@ <meta http-equiv="Content-type" content='text/html; charset="US-ASCII"' /> <meta name="DC.Creator" content="Eggert, Paul" /> <meta name="DC.Contributor" content="Olson, Arthur David" /> -<meta name="DC.Date" content="2005-01-11" /> +<meta name="DC.Date" content="2005-03-11" /> <meta name="DC.Description" content="Sources of information about time zones and daylight saving time" /> <meta name="DC.Identifier" content="http://www.twinsun.com/tz/tz-link.htm" /> @@ -224,8 +224,10 @@ Java-specific format.</li> href="http://www1.tip.nl/~t876506/AboutTimeZonesHC.html">HyperCard time zones calculator</a> is a HyperCard stack.</li> <li><a -href="http://www.veladesigngroup.com/velaterra.html">VelaTerra</a> is -a Mac OS X program.</li> +href="http://www.veladg.com/velaterra.html">VelaTerra</a> is +a Mac OS X program. Its developers +<a href="http://www.veladg.com/tzoffer.html">offer free +licenses</a> to <code>tz</code> contributors.</li> <li><a href="http://www.cimmyt.org/timezone/">World Time Explorer</a> is a Microsoft Windows program.</li>

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RE: Is more detailed timezone history desired?
by Olson, Arthur David (NIH/NCI) March 10, 2005

March 10, 2005

Top priorities would be: 1. Ensure that the format of the time zone source files is adequate to represent historical changes. 2. Document changes since 1970-01-01 (the POSIX epoch). --ado -----Original Message----- From: Alois Treindl [mailto:alois@astro.ch] Sent: Thursday, March 10, 2005 4:54 PM To: tz(a)lecserver.nci.nih.gov Subject: Is more detailed timezone history desired? regarding my project to extend the details of timezone history in tzdata, a first question: Is it desirable, in the eyes of current tzdata maintainers, to add such extensions?

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Time zone: the next generation
by Olson, Arthur David (NIH/NCI) March 10, 2005

March 10, 2005

Time zone package: the next generation Over the last year we've done as much as possible, within the existing time zone package framework, to cope with systems with 64-bit time_t values. But the zone information compiler (zic) still produces binary files with 32-bit transition time values. Something's gotta give. As long as we're making changes, it's best to do as much as possible (to avoid the need for further change down the road). I've listed problems, approaches, and questions below. Much of this material is related to general matters of time rather than specific matters of time zones; my apologies. PROBLEMS * Future transition times/past transition times The binary files produced by zic record transition times as 32-bit values; times after the 2038 (or before 1901) cannot be represented. (The future limit can be extended to 2106 by treating the values as unsigned, but if that's done times before 1970 cannot be represented.) * Transitions in Israel Israel now goes back to standard time in the fall on the Saturday before Yom Kippur; there's no convenient way to represent this in the input to zic. * Julian-Gregorian transition Signed 32-bit time_t values can only represent years going back to 1901; this means that for most areas of the world the Gregorian calendar is in effect for all times representable by such a time_t. Signed 64-bit time_t values have a far greater range; the range always includes all instants when areas switched from Julian to Gregorian. There's no provision for handling the switch in the time zone package. (The transition happens at different times in different places; in addition to handling the jump over a number of days, there's also the matter of figuring out whether a year ending in 00 is a leap year in a particular place.) * Year zero Some year numbering schemes skip over the year zero; others do not. There's no provision for specifying whether or not to skip in the time zone package. * Early years of Julian calendar Leap years were inserted every three (rather than four) years early in the life of the Julian calendar; some leap years were skipped later to make up for this. Month lengths (and names) were also in flux for a while. Documentation of the glitches is shaky; there's no way to reflect what documentation we do have. * Pre-Julian calendars The time zone package cannot handle information about the Roman Republic calendar or any of its predecessors. * Non-Julian-Gregorian calendars The time zone package cannot handle information about non-Julian-Gregorian time schemes (Mayan, Martian, and so on). * Big Bang/Big Crunch Signed 64-bit time_t values have enough range to go back to theorized time of the Big Bang origin of the universe and thus back to the start of time itself. Some folks might want to fold all instants "before" the Big Bang in to that instant. At the other end, advocates of the Big Crunch theory might want to treat time_t values greater than the predicted Crunch instant as if they were the Crunch instant. There's no way to do such pegging in the time zone package. * Creation/Apocalypse Some folks might want to peg past times at a predicted time of Creation and peg future times at a predicted Apocalypse. APPROACHES * Do nothing Since things don't get sticky until at least 2037, it's possible to wait (at least for a while) before taking action. * Tweak the binary file format At the least this would involve widening stored transition times beyond 32 bits. It might also be necessary to widen offsets as a way of coping with Julian/Gregorian shifts and year zero skips. * Abandon binary files We're now operating on the "terminfo" model in which human-readable descriptions are converted to binary form (with some precomputation done) for use by programs. We could shift to the earlier "termcap" model, simply copying files such as "asia" and "northamerica" to a public directory and interpreting them at run time. This eliminates the need to change binary file formats (since such files disappear); there might still be a need to change the source file format if we wanted to do things such as handle Julian/Gregorian transitions. Responsibly taking this approach might involve learning why the termcap-to-terminfo transition occurred, and whether the reasons are still applicable in today's computing environment. * Preprocess We could change "zic" so that for each zone it outputs a file with only those Rule and Zone lines required for the zone; there could be some simplification of the output (such as expressing all times in UTC) to ease interpretation. Again there would be run-time interpretation, but the job would be scaled down (by pre-identification of relevant data) and simplified. * Change zic's output to another format We could take the vzic route of reading the existing source files and producing VZONEINFO format output. We might want to extend the VZONEINFO format (for example, to handle leap seconds). We might want to produce output in some other existing format, or in a newly designed format. QUESTIONS * Do we handle Julian/Gregorian transitions? * Do we allow control of skipping the year zero? * Do we handle early-Julian leap year variations? * Do we handle pegging of far-past and far-future times? * For each new of the above: * What default assumption should be used in zic and in run-time software? * Can the assumption be overridden in a time zone source file? If so, how? * Can the assumption be overridden using an environment variable? If so, how? * Can the assumption be overridden with function calls? If so, how? * Do we simplify handling of events tied to non-Gregorian-calendar-related events (such as Yom Kippur)? * Do we handle pre-Julian or non-Julian-Gregorian time schemes? * When Sherman types... %horton TZ=Europe/Rome wayback March 15 -44 ...will he and Mr. Peabody witness an assassination? So...before discussing any of the above in detail...are the problems, approaches, and questions above correct and complete? If not, what should be changed? --ado

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Timezone converstion
by Rajesh Vargheese March 10, 2005

March 10, 2005

Hello, I was trying to evaluate tz libs for timezone usage for my application. My need: Given a region id [ex. "America/New_York"] and a UTC time, i want to get the offset i need to get the time for that region. I also need the Day light savings to be accounted. Can I use the libtz library to do this. Please let me if there are any location where I can get some sample code in C/C++ to do this. I tried to get the old archive so that I can find an answer, but its erroring out. Thanks in advance, Rajesh

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FW: Time zone: the next generation
by Olson, Arthur David (NIH/NCI) March 10, 2005

March 10, 2005

Since sending this message, Alois has joined the time zone mailing list. --ado -----Original Message----- From: Alois Treindl [mailto:alois@astro.ch] Sent: Thursday, March 10, 2005 5:54 AM To: Olson, Arthur David (NIH/NCI) Cc: Tz (tz(a)elsie.nci.nih.gov) Subject: Re: Time zone: the next generation On Thu, 3 Mar 2005, Olson, Arthur David (NIH/NCI) wrote: > QUESTIONS > > * Do we handle Julian/Gregorian transitions? Yes, but with an override feature in the API. One of the problems is that many history texts contain converted calendar dates. For the consistency of a particular history book, biography etc, authors have a tendency to convert all calendar data contained in them into one system, even if at the given date and location a different calendar might have applied. If a related calendar/timezone database makes strict assumptions about which calendar applied for a given date, then new problems are introduced. > * Do we allow control of skipping the year zero? Both styles of year counting have a name. The one with year zero is called 'astronomical year counting style' and it indicates years BC with negative year numbers. The one without year zero is called 'historical year counting style' and it indicates years BC with the suffix BC or BCE or something similar, but never with a plus/minus sign. I think the documentation should be clear, but the API needs only to support one style. > * Do we handle pegging of far-past and far-future times? Aside from calendar system changes, no time zone data are known for dates before the 1800s. There is an issue whether true solar time or mean solar time was used for the recording of a particular historical event. But I do not see how tzdata should be able to answer this question. E.g. when J.W.Goethe mentions in one of his works that he was born at noon on 28 August 1749 (greg. calendar) in Frankfurt: Does he mean true solar time (as indicated by a sun dial) or mean solar time (as measured by an astronomical clock in an observatory)? tzdata cannot know this, and should not claim that it knows. There was no clear transition between true solar time and mean solar time reckoning, before the formal introduction of timezone standards in the 19th century. Alois Treindl

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Who ist the maintainer of tzdata?
by Alois Treindl March 10, 2005

March 10, 2005

I have a project to expand tzdata. Summarizing shortly, the rough idea is to - add boundary descriptions to each area with a different timezone history so that with given coordinates it can automatically be determined to which timezone history 'table' a given location belongs. I am aware that many non-trivial issues of geo-information processing arise with such a goal. - add more details for the complicated timezone history of some countries, e.g. Canada, where other sources have identified more than 250 regions with different timezone history, whereas current tzdata has only 15 regions. I am aware that this is a large project which will require resources measured in man-years. I may be in a position to contribute/sponsor such resources. I would like to communicate with the current maintainers of tzdata about these ideas, and about the best approach for such an expansion. My motivation background is the field of serious astrology, where reliable timezone history information is an essential requirement. tzdata is doing an excellent job to provide reliable information for current timzones, but it lacks sadly (and understandably, given the complexity of the problem) in historical detail. Alois Treindl

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RE: Time zone: the next generation (future transitions)
by Olson, Arthur David (NIH/NCI) March 8, 2005

March 8, 2005

The Gregorian calendar cycles every 400 years: January 1 fell on a [Saturday] in 2000, and will do so again in 2400. In a traditional-zic approach, we could store 400 (or more) years worth of future transitions; stuff beyond that could be handled at run time. For example, a localtime call would, for far future times: cast out 400 years worth of seconds at a time to get to the near future (remembering how many years worth of seconds had been cast out); convert the resulting time_t value; and add the cast-off number of years to the resulting time_t value. We'd of course need to check at run time to verify that this was the right approach. --ado

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Olson database name ambiguity
by Tom Yandell March 7, 2005

March 7, 2005

Hi Apologies for cross posting this. I think that this is a problem in the data in the Olson database, but as it is a binary format it is difficult to verify this. I have come across this problem using the DateTime perl module (version 0.28) whose data is generated from the Olson database. The problem that I am experiencing is that the short name for timezones for 'Europe/London' up until 1996 were either 'GMT' or 'BST' (depending if daylight saving changes were in effect). From 1996 the name for the timezone is the rather less precise 'GMT/BST' regardless of whether daylight saving changes are in effect or not. I have attached a script that demonstrates this, and its output. Regards, Tom

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Re: FW: Time zone: the next generation
by kennykb＠crd.ge.com March 4, 2005

March 4, 2005

Clive Feather posts some interesting historical observations about the calendar, which I suppressed from my original posting because I thought that they'd drown the readers in irrelevant detail -- a one-line summary, in my arrogant opinion, is "we don't want to go there." -- 73 de ke9tv/2, Kevin KENNY GE Corporate Research & Development kennykb(a)crd.ge.com P. O. Box 8, Bldg. K-1, Rm. 5B36A Schenectady, New York 12301-0008 USA

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FW: Time zone: the next generation
by Olson, Arthur David (NIH/NCI) March 4, 2005

March 4, 2005

Kevin Kenny is on the time zone mailing list, but at a different address than that shown below. --ado -----Original Message----- From: kennykb(a)crd.ge.com [mailto:kennykb@crd.ge.com] Sent: Thursday, March 03, 2005 3:22 PM To: Tz (tz(a)elsie.nci.nih.gov) Subject: Re: Time zone: the next generation I've done a good bit of similar code for the Tcl programming language (see http://www.tcl.tk/cgi-bin/tct/tip/173 for details). The implementation there can handle the proleptic Julian calendar, with a defined change date. There are a number of caveats worth mentioning: - Prior to the Julian conversion, different locales had different rules for when the number of the year changed. In and before 1752 in Great Britain, for instance, the number of the year changed on 25 March; 1-24 March belonged to the previous year! With the adoption of the Gregorian calendar, the change was universally 1 January. (For this reason, you'll sometimes see eighteenth-century dates as O.S. ("Old Style") or N.S. ("New Style") when the year would otherwise be ambiguous. I decided for Tcl not to bother with any kind of localized rule for year numbering in those circumstances; it was too much of a mess. - As you correctly observe, leap years were observed irregularly in Rome in Republican and early Imperial times. In fact, they were so irregularly observed that it was occasionally necessary to intercalate entire months. Again, I decided with Tcl not to bother. - It appears unnecessary to control skipping the year zero. I have not encountered any locale where there is such a beast; in all cases, it appears that the year 1 B.C.E. is followed by the year 1 C.E. - I use a message catalog (the same catalog in which I hold localised month names) to hold a locale's Julian conversion date, and then select the catalog according to LC_TIME. Tcl's ordinary message catalog functionality can be used to change the date. - I have not yet troubled to implement anything but Gregorian (or hybrid Julian-Gregorian) calendars. I did a limited amount of localization to handle the Japanese civil calendar, but only for dates after the Meiji restoration (when it's Gregorian, except that years number from the start of an emperor's reign). Incidentally, Tcl's counterpart to zic (which uses the same input format as zic) simply uses 64-bit counts of seconds for its transition times. Also, it doesn't track leap seconds, since Tcl's model of time is Markus Kuhn's "smoothed universal time" (http://www.cl.cam.ac.uk/~mgk25/uts.txt) in which leap seconds are handled by changing the length of a second by 1 part in 1000 until Tcl's clock is back in sync with UTC. -- 73 de ke9tv/2, Kevin KENNY GE Corporate Research & Development kennykb(a)crd.ge.com P. O. Box 8, Bldg. K-1, Rm. 5B36A Schenectady, New York 12301-0008 USA

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Re: Time zone: the next generation
by kennykb＠crd.ge.com March 3, 2005

March 3, 2005

I've done a good bit of similar code for the Tcl programming language (see http://www.tcl.tk/cgi-bin/tct/tip/173 for details). The implementation there can handle the proleptic Julian calendar, with a defined change date. There are a number of caveats worth mentioning: - Prior to the Julian conversion, different locales had different rules for when the number of the year changed. In and before 1752 in Great Britain, for instance, the number of the year changed on 25 March; 1-24 March belonged to the previous year! With the adoption of the Gregorian calendar, the change was universally 1 January. (For this reason, you'll sometimes see eighteenth-century dates as O.S. ("Old Style") or N.S. ("New Style") when the year would otherwise be ambiguous. I decided for Tcl not to bother with any kind of localized rule for year numbering in those circumstances; it was too much of a mess. - As you correctly observe, leap years were observed irregularly in Rome in Republican and early Imperial times. In fact, they were so irregularly observed that it was occasionally necessary to intercalate entire months. Again, I decided with Tcl not to bother. - It appears unnecessary to control skipping the year zero. I have not encountered any locale where there is such a beast; in all cases, it appears that the year 1 B.C.E. is followed by the year 1 C.E. - I use a message catalog (the same catalog in which I hold localised month names) to hold a locale's Julian conversion date, and then select the catalog according to LC_TIME. Tcl's ordinary message catalog functionality can be used to change the date. - I have not yet troubled to implement anything but Gregorian (or hybrid Julian-Gregorian) calendars. I did a limited amount of localization to handle the Japanese civil calendar, but only for dates after the Meiji restoration (when it's Gregorian, except that years number from the start of an emperor's reign). Incidentally, Tcl's counterpart to zic (which uses the same input format as zic) simply uses 64-bit counts of seconds for its transition times. Also, it doesn't track leap seconds, since Tcl's model of time is Markus Kuhn's "smoothed universal time" (http://www.cl.cam.ac.uk/~mgk25/uts.txt) in which leap seconds are handled by changing the length of a second by 1 part in 1000 until Tcl's clock is back in sync with UTC. -- 73 de ke9tv/2, Kevin KENNY GE Corporate Research & Development kennykb(a)crd.ge.com P. O. Box 8, Bldg. K-1, Rm. 5B36A Schenectady, New York 12301-0008 USA

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Timezone Dates for Israel [2005 and beyond]
by Ephraim Silverberg March 2, 2005

March 2, 2005

>From now on, Daylight Saving Time in the State of Israel will commence at 02:00 a.m. on the first Friday before April 2nd and will last until 02:00 a.m. on the first Sunday before the Jewish fast of Yom Kippur. The proposed law amendment can be viewed (for those who read Hebrew) at: ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2005+beyond.ps Note that although the wording of the law is not final, its intent is -- a free translation of the text would read: Every year, between the last Friday of the month of March, at 02:00, and the last Sunday before the tenth of [the Hebrew month of] Tishrei [i.e. the fast of Yom Kippur], at 02:00, the time in Israel will be made one hour earlier so that it will precede Coordinated Universal Time by three hours; in a year that the first of April falls on a Friday, the time will be made earlier, in the manner mentioned, in that year, on this day at 02:00. Attached to this message are the context diffs for "tzdata2005e/asia". I have also update the ZIC entry Emacs generator at: ftp://ftp.cs.huji.ac.il/pub/tz/software/dst-israel.el although it does not use year-range short-hand notation and produces explicit dates for each year. ___________________________________________________________________________ Ephraim Silverberg, CSE System Group, Phone number: 972-2-6585521 Hebrew University, Jerusalem, Israel. Fax number: 972-2-5617723 WWW: http://www.cs.huji.ac.il/~ephraim E-mail: ephraim(a)cse.huji.ac.il

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Tzcode2005f.tar.gz and tzdata2005f.tar.gz
by Olson, Arthur David (NIH/NCI) March 1, 2005

March 1, 2005

The files... ftp://elsie.nci.nih.gov/pub/tzcode2005f.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2005f.tar.gz ...are now available; these include the data and documentation changes circulated on the time zone mailing list last week by Paul Eggert. --ado

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FW: Question about: TWiki.org Service: Date and Time Gateway
by Olson, Arthur David (NIH/NCI) Feb. 23, 2005

Feb. 23, 2005

Neither Peter nor Krystian is on the time zone mailing list; direct replies appropriately. --ado -----Original Message----- From: Peter Thoeny [mailto:peter.thoeny@attglobal.net] Sent: Sunday, February 13, 2005 6:23 PM To: krystian(a)mindspring.com; tz(a)lecserver.nci.nih.gov Subject: Re: Question about: TWiki.org Service: Date and Time Gateway Dear Krystian and tz team, The program on TWiki.org takes the data from the Olson tz database, http://www.twinsun.com/tz/tz-link.htm I am not sure I can explain the +/- GMT question, someone from the Olson tz database team is probably better in that. More info on GMT at http://en.wikipedia.org/wiki/GMT Info on timezones at http://wwp.greenwichmeantime.com/info/timezone.htm Interstingly, above site shows GMT times in reverse to the Olson database! E.g. for me in California, the Olson database tells me I am in Etc/GMT+8, and greenwichmeantime.com tells me I am GMT-8. Regards, Confused Peter krystian(a)mindspring.com wrote: > > This question pertains to the data within: > > TWiki.org Service: Date and Time Gateway > http://twiki.org/cgi-bin/xtra/tzdate > > Which I believe is under a revision by your penmanship. > > Q. Are the GMT offsets mixed in this website? When I think of GMT-5 I > think of Eastern Standard Time, however your site lists GMT-5 as where > I always think GMT+5 is. > > > Greenwich Mean Time: (GMT/UCT/UTC/Universal/Zulu; positive numbers > > count hours west of GMT > > What is the cause of having positive numbers count west of GMT? Aren't > positive numbers, by definition, to be east of GMT? (like GMT+5 is add > 5 hours to the time at GMT?) > > I've seen lots of confusion about this on the web and I don't > understand why this is so. I have always thought GMT-5 was Eastern > Standard Time, not some time in the European longitudes. > > Can you please speculate on this? I'm also trying to find the > difference between UTC and GMT (as I've read they are the same but not > exactly). Maybe this is how they differ. > > I'm terribly confused. Please offer an explanation to your readers in > the form of a link or direct them to such a place. > > Regards, > Roland Krystian Alberciak. -- * Peter Thoeny Peter(a)Thoeny.com * Is your team already TWiki enabled? http://TWiki.org * This e-mail is: (_) public (x) ask first (_) private

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Re: Question about: TWiki.org Service: Date and Time Gateway
by Peter Thoeny Feb. 13, 2005

Feb. 13, 2005

Dear Krystian and tz team, The program on TWiki.org takes the data from the Olson tz database, http://www.twinsun.com/tz/tz-link.htm I am not sure I can explain the +/- GMT question, someone from the Olson tz database team is probably better in that. More info on GMT at http://en.wikipedia.org/wiki/GMT Info on timezones at http://wwp.greenwichmeantime.com/info/timezone.htm Interstingly, above site shows GMT times in reverse to the Olson database! E.g. for me in California, the Olson database tells me I am in Etc/GMT+8, and greenwichmeantime.com tells me I am GMT-8. Regards, Confused Peter krystian(a)mindspring.com wrote: > > This question pertains to the data within: > > TWiki.org Service: Date and Time Gateway > http://twiki.org/cgi-bin/xtra/tzdate > > Which I believe is under a revision by your penmanship. > > Q. Are the GMT offsets mixed in this website? When I think of GMT-5 I think > of Eastern Standard Time, however your site lists GMT-5 as where I always > think GMT+5 is. > > > Greenwich Mean Time: (GMT/UCT/UTC/Universal/Zulu; > > positive numbers count hours west of GMT > > What is the cause of having positive numbers count west of GMT? Aren't > positive numbers, by definition, to be east of GMT? (like GMT+5 is add 5 > hours to the time at GMT?) > > I've seen lots of confusion about this on the web and I don't understand why > this is so. I have always thought GMT-5 was Eastern Standard Time, not some > time in the European longitudes. > > Can you please speculate on this? I'm also trying to find the difference > between UTC and GMT (as I've read they are the same but not exactly). Maybe > this is how they differ. > > I'm terribly confused. Please offer an explanation to your readers in the > form of a link or direct them to such a place. > > Regards, > Roland Krystian Alberciak. -- * Peter Thoeny Peter(a)Thoeny.com * Is your team already TWiki enabled? http://TWiki.org * This e-mail is: (_) public (x) ask first (_) private

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Tzcode2005e.tar.gz and tzdata2005e.tar.gz
by Olson, Arthur David (NIH/NCI) Feb. 10, 2005

Feb. 10, 2005

The files... ftp://elsie.nci.nih.gov/pub/tzcode2005e.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2005e.tar.gz ...are now available; these incorporate the changes circulated last week on the time zone mailing list. My fond hope is the above code is stable for now; it's time for a design phase to figure out what else (if anything) to do to cope with 64-bit time_t values. Details to follow. --ado

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Re: Israel 2005 and Beyond -- Proposed Timezone Dates
by Paul Eggert Feb. 8, 2005

Feb. 8, 2005

Ephraim Silverberg <ephraim(a)cse.huji.ac.il> writes: > emacs -batch -l dst-israel.el > > ... If the law passes, I'll put the script in the Israel TZ ftp depository. Thanks for doing that! A couple of minor comments. First, the existing database uses "Apr<tab>25" and "Apr<tab><space>9" rather than "Apr<space>25" and "Apr<space><space>9". Also, it'd be a bit handier to input a range of dates rather than a single date. I used your program to write the following draft patch. I don't think this should go into the tz database just yet (Israeli politics being what they are) but I thought you might like to see the draft. Thanks again. --- asia 2004/10/11 18:44:51 2004.5 +++ asia 2004/12/22 23:00:21 @@ -639,7 +639,7 @@ Rule Zion 1988 only - Apr 9 0:00 1:00 D Rule Zion 1988 only - Sep 3 0:00 0 S # From Ephraim Silverberg <ephraim(a)cs.huji.ac.il> -# (1997-03-04, 1998-03-16, 1998-12-28, 2000-01-17 and 2000-07-25): +# (1997-03-04, 1998-03-16, 1998-12-28, 2000-01-17, 2000-07-25, and 2004-12-22): # According to the Office of the Secretary General of the Ministry of # Interior, there is NO set rule for Daylight-Savings/Standard time changes. @@ -690,13 +690,13 @@ Rule Zion 1995 only - Sep 3 0:00 0 S # time, Haim Ramon. The official announcement regarding 1996-1998 # (with the dates for 1997-1998 no longer being relevant) can be viewed at: # -# ftp://ftp.huji.ac.il/pub/tz/announcements/1996-1998.ramon.ps.gz +# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/1996-1998.ramon.ps.gz # # The dates for 1997-1998 were altered by his successor, Rabbi Eli Suissa. # # The official announcements for the years 1997-1999 can be viewed at: # -# ftp://ftp.huji.ac.il/pub/tz/announcements/YYYY.ps.gz +# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/YYYY.ps.gz # # where YYYY is the relevant year. @@ -716,12 +716,12 @@ Rule Zion 1999 only - Sep 3 2:00 0 S # # The official announcement for the start date of 2000 can be viewed at: # -# ftp://ftp.huji.ac.il/pub/tz/announcements/2000-start.ps.gz +# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2000-start.ps.gz # # The official announcement for the end date of 2000 and the dates # for the years 2001-2004 can be viewed at: # -# ftp://ftp.huji.ac.il/pub/tz/announcements/2000-2004.ps.gz +# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2000-2004.ps.gz # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Zion 2000 only - Apr 14 2:00 1:00 D @@ -735,52 +735,97 @@ Rule Zion 2003 only - Oct 3 1:00 0 S Rule Zion 2004 only - Apr 7 1:00 1:00 D Rule Zion 2004 only - Sep 22 1:00 0 S -# From Paul Eggert (2000-07-25): -# Here are guesses for rules after 2004. -# They are probably wrong, but they are more likely than no DST at all. +# Yesterday, the Knesset Interior Committee passed a proposed (originally +# in March 2004) change to the Time Setting Law that would make the dates +# for DST from 2005 and beyond so that DST starts on the night _after_ the +# first night of the Passover holiday at midnight until midnight of the +# Saturday night _before_ the fast of Yom Kippur. +# +# Those who can read Hebrew can view the proposal at: +# +# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2005+.ps +# +# The proposal still has to be passed by the Knesset (three readings) for +# it to become law.... + +# From Paul Eggert (2004-12-22): +# For now, guess that the rules proposed on 2004-12-20 will be adopted. +# This is quite possibly wrong, but it is more likely than no DST at all. +# I used Ed Reingold's cal-hebrew in GNU Emacs 21.3, along with code +# written by Ephraim Silverberg, to generate this list. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Zion 2005 max - Apr 1 1:00 1:00 D -Rule Zion 2005 max - Oct 1 1:00 0 S +Rule Zion 2005 only - Apr 25 0:00 1:00 D +Rule Zion 2005 only - Oct 9 0:00 0 S +Rule Zion 2006 only - Apr 14 0:00 1:00 D +Rule Zion 2006 only - Oct 1 0:00 0 S +Rule Zion 2007 only - Apr 4 0:00 1:00 D +Rule Zion 2007 only - Sep 16 0:00 0 S +Rule Zion 2008 only - Apr 21 0:00 1:00 D +Rule Zion 2008 only - Oct 5 0:00 0 S +Rule Zion 2009 only - Apr 10 0:00 1:00 D +Rule Zion 2009 only - Sep 27 0:00 0 S +Rule Zion 2010 only - Mar 31 0:00 1:00 D +Rule Zion 2010 only - Sep 12 0:00 0 S +Rule Zion 2011 only - Apr 20 0:00 1:00 D +Rule Zion 2011 only - Oct 2 0:00 0 S +Rule Zion 2012 only - Apr 8 0:00 1:00 D +Rule Zion 2012 only - Sep 23 0:00 0 S +Rule Zion 2013 only - Mar 27 0:00 1:00 D +Rule Zion 2013 only - Sep 8 0:00 0 S +Rule Zion 2014 only - Apr 16 0:00 1:00 D +Rule Zion 2014 only - Sep 28 0:00 0 S +Rule Zion 2015 only - Apr 5 0:00 1:00 D +Rule Zion 2015 only - Sep 20 0:00 0 S +Rule Zion 2016 only - Apr 24 0:00 1:00 D +Rule Zion 2016 only - Oct 9 0:00 0 S +Rule Zion 2017 only - Apr 12 0:00 1:00 D +Rule Zion 2017 only - Sep 24 0:00 0 S +Rule Zion 2018 only - Apr 1 0:00 1:00 D +Rule Zion 2018 only - Sep 16 0:00 0 S +Rule Zion 2019 only - Apr 21 0:00 1:00 D +Rule Zion 2019 only - Oct 6 0:00 0 S +Rule Zion 2020 only - Apr 10 0:00 1:00 D +Rule Zion 2020 only - Sep 27 0:00 0 S +Rule Zion 2021 only - Mar 29 0:00 1:00 D +Rule Zion 2021 only - Sep 12 0:00 0 S +Rule Zion 2022 only - Apr 17 0:00 1:00 D +Rule Zion 2022 only - Oct 2 0:00 0 S +Rule Zion 2023 only - Apr 7 0:00 1:00 D +Rule Zion 2023 only - Sep 24 0:00 0 S +Rule Zion 2024 only - Apr 24 0:00 1:00 D +Rule Zion 2024 only - Oct 6 0:00 0 S +Rule Zion 2025 only - Apr 14 0:00 1:00 D +Rule Zion 2025 only - Sep 28 0:00 0 S +Rule Zion 2026 only - Apr 3 0:00 1:00 D +Rule Zion 2026 only - Sep 20 0:00 0 S +Rule Zion 2027 only - Apr 23 0:00 1:00 D +Rule Zion 2027 only - Oct 10 0:00 0 S +Rule Zion 2028 only - Apr 12 0:00 1:00 D +Rule Zion 2028 only - Sep 24 0:00 0 S +Rule Zion 2029 only - Apr 1 0:00 1:00 D +Rule Zion 2029 only - Sep 16 0:00 0 S +Rule Zion 2030 only - Apr 19 0:00 1:00 D +Rule Zion 2030 only - Oct 6 0:00 0 S +Rule Zion 2031 only - Apr 9 0:00 1:00 D +Rule Zion 2031 only - Sep 21 0:00 0 S +Rule Zion 2032 only - Mar 28 0:00 1:00 D +Rule Zion 2032 only - Sep 12 0:00 0 S +Rule Zion 2033 only - Apr 15 0:00 1:00 D +Rule Zion 2033 only - Oct 2 0:00 0 S +Rule Zion 2034 only - Apr 5 0:00 1:00 D +Rule Zion 2034 only - Sep 17 0:00 0 S +Rule Zion 2035 only - Apr 25 0:00 1:00 D +Rule Zion 2035 only - Oct 7 0:00 0 S +Rule Zion 2036 only - Apr 13 0:00 1:00 D +Rule Zion 2036 only - Sep 28 0:00 0 S +Rule Zion 2037 only - Apr 1 0:00 1:00 D +Rule Zion 2037 only - Sep 13 0:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Jerusalem 2:20:56 - LMT 1880 2:20:40 - JMT 1918 # Jerusalem Mean Time? 2:00 Zion I%sT -# From Ephraim Silverberg (2003-03-23): -# -# Minister of Interior Poraz has announced that he will respect the law -# passed in July 2000 (proposed at the time jointly by himself and -# then-MK David Azulai [Shas]) fixing the dates for 2000-2004. Hence, -# the dates for 2003 and 2004 remain unchanged.... -# -# As far as 2005 and beyond, no dates have been set. However, the -# minister has mentioned that he wishes to propose to move Israel's -# timezone in 2005 from GMT+2 to GMT+3 and upon that have DST during -# the summer months (i.e. GMT+4). However, no legislation in this -# direction is expected until the latter part of 2004 which is a long -# time off in terms of Israeli politics. - -# (2004-09-20): -# The latest rumour, however, is that in 2005, when the clock changes to -# Daylight Saving Time (date as yet unknown), the move will be a two-hour leap -# forward (from UTC+0200 to UTC+0400) and then, in the fall, the clock will -# move back only an hour to UTC+0300 thus effectively moving Israel's timezone -# from UTC+0200 to UTC+0300. However, no actual draft has been put before the -# Knesset (Israel's Parliament) though the intention is to do so this -# month [2004-09]. - -# (2004-09-26): -# Even though the draft law for the above did pass the Ministerial Committee -# for Legislative Matters three months ago, it was voted down in today's -# Cabinet meeting. The current suggestion is to keep the current timezone at -# UTC+0200 but have an extended period of Daylight Saving Time (UTC+0300) from -# the beginning of Passover holiday in the spring to after the Tabernacle -# holiday in the fall (i.e. the dates of which are governed by the Hebrew -# calendar but this means at least 184 days of DST). However, this is only a -# suggestion that was raised in today's cabinet meeting and has not yet been -# drafted. - ###############################################################################

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FW: IANA time zone registration - proposal
by Olson, Arthur David (NIH/NCI) Feb. 7, 2005

Feb. 7, 2005

Doug Royer is not on the time zone mailing list; direct replies appropriately. --ado -----Original Message----- From: Doug Royer [mailto:Doug@Royer.com] Sent: Monday, January 17, 2005 2:12 PM To: tz(a)lecserver.nci.nih.gov Subject: IANA time zone registration - proposal [This was sent to some IETF mailing lists by me and someone suggested I send it to this list also] This is REV -00 of the proposal - comments welcome. Data in in it can easily updated. (Like the TZ names updated to latest copy of data) ---------------------------------------------------- A couple of years ago there was talk on the CALSCH mailing list to have an IANA time zone registration process. I have submitted a proposal for that registry to the IETF. A copy can be found at: http://inet-consulting.com/draft-royer-timezone-registry-00.txt And an HTML version: http://inet-consulting.com/draft-royer-timezone-registry-00.html I am adding the POLYGON property targeted for the -01 version that has an ADD/DELETE parameter to allow for the optional inclusion of latitude/longitude geographic areas to be included that include (add) and exclude (delete) areas from the time zone geographic region (again from the CALSCH mailing list discussions). -- Doug Royer | http://INET-Consulting.com -------------------------------|----------------------------- Doug(a)Royer.com | Office: (208)612-4638 http://Royer.com | Fax: (866)594-8574 | Cell: (208)520-4044 We Do Standards - You Need Standards

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