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Corrections to latitudes/longitudes in zone.tab
by Andy McDonald May 23, 2006

May 23, 2006

Hi, A very very minor point, but I've run across a few inaccurate latitudes/longitudes in tz's zone.tab (2006g and earlier): Corrected lat/long zone.tab lat/long America/Argentina/Tucuman: -0265000, -0651300 -0312400, -0641100 America/Inuvik: +0682200, -1334400 +0682500, -1133000 America/Rainy_River: +0484300, -0943400 +0484300, -0942900 America/Rankin_Inlet +0624800, -0920500 +0624500, -0921000 America/Scoresbysund: +0703000, -0215800 +0703000, -0221500 (Tucuman's latitude and longitude in zone.tab are those of America/Argentina/Cordoba.) The corrected values come from playing with my Firefox extension (http://www.stemhaus.com/firefox/foxclocks/) and Google Earth, and are of course entirely subjective. Regards, Andy McDonald

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timezones offset from what?
by Zefram May 19, 2006

May 19, 2006

I've been doing work on precision timekeeping on computer systems. Naturally I don't use timezones at all inside that code, but there are places where I need to apply timezones when presenting a time to non-specialist humans. Looking through the zoneinfo database and the theory written about it, it struck me that although it deals fantastically with what time offset to use, there's no rigorous treatment of what base time scale to apply the offset to. Then it struck me that a simple treatment of this could solve a couple of other issues with the database. An example of this issue: as the zoneinfo source notes, UK legal time is currently based on mean solar time on the Greenwich meridian. Now that's not even Universal Time any more, since the prime meridian moved (slightly) off the Greenwich meridian. But everyone in the UK in practice sets their clocks based on UTC, as promulgated by the NPL and the BBC. At centisecond timescales, GMT (legal time in the UK), UTC (used in practice), UT1 (which UTC tracks in the long term), and UT2 (used for civil time in the 1950s) are all quite distinct. So I have a suggestion: it would be nice if the zoneinfo database included a field identifying exactly which time scale to apply the offsets to. The database doesn't need to understand how the time scales relate to each other; leave that to the precision horologists. All it needs is a short text string, with values such as "UTC", "UT1", "GMT". Of course, in a lot of cases this information is unavailable, or the distinction wasn't being made, so you'd then give "UT" to be explicitly ambiguous about the exact flavour of Universal Time. This field would also allow the database to handle timezones that are based on something other than UT. Currently the data files for Saudi Arabia attempt to describe apparent solar time in terms of UT, by means of a daily offset change. But it could instead be specified as a fixed offset with a base of apparent solar time on the prime meridian. To understand the zone properly the code would need to calculate the equation of time, but that only needs to be implemented once and it would give a much smoother and more accurate result than the daily UT offset changes do. A system that doesn't do the equation of time would effectively fall back to mean solar time, which is what the Riyadh8X zones do anyway. It's also a way to handle Mars time. Just specify the base to be MTC instead of UT. Ta da. What do you think? -zefram

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Correction
by Behdad Elahipanah May 17, 2006

May 17, 2006

Tehran's (Iran) current UTC/GMT Offset is: +3:30 hours with no daylight saving time at the moment Please correct it in your database.

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Kirov on GMT+4?
by Jesper Norgaard Welen May 16, 2006

May 16, 2006

The Kirov timezone according to the tz database is GMT+3. As you will remember in an earlier mail I could not find any mention of the timezone directly in the page of the Kirovskaya oblast' in http://www.gov-vyatka.ru/ however this page pointed to another page http://www.gismeteo.ru/weather/towns/27196.htm that has sunrise and sunset times indicating that Kirov is on GMT+3. Now I have found a page that points to this same page, but explicitly defines Kirov as being on GMT+4: >From main page http://map.rin.ru selecting Kirovskaya obl. http://map.rin.ru/cgi-bin/main.pl?Region=kirov you can see just below the link to the www.gismeteo.ru link that it specifies explicitly GMT+4 The other links confirm what we think for other oblast's in the area: Samarskaya oblast' on GMT+4: http://map.rin.ru/cgi-bin/main.pl?Region=samara Udmurtskaya oblast' on GMT+4: http://map.rin.ru/cgi-bin/main.pl?Region=udmurt Volgogradskaya oblast' on GMT+3: http://map.rin.ru/cgi-bin/main.pl?Region=volga Astrakhanskaya oblast' on GMT+3: http://map.rin.ru/cgi-bin/main.pl?Region=astrah Saratovskaya oblast' on GMT+3: http://map.rin.ru/cgi-bin/main.pl?Region=saratov Komi republic on GMT+3: http://map.rin.ru/cgi-bin/main.pl?Region=komi This page has a summary of time differences from Moscow time, and shows Kirov as being on Moscow time, e.g. GMT+3: http://www.bereg.ru/sprav_info/inform/time.shtml As we know from an earlier email from Paul Eggert, Shanks & Pottenger (2003) has Kirov on GMT+4. I'm afraid Kirov is a difficult case. I have changed it myself in World Time Explorer 4 times from between GMT+4 and GMT+3: February 23, 2000 GMT+4 to GMT+3 January 21, 2001 GMT+3 to GMT+4 June 18, 2001 GMT+4 to GMT+3 October 2, 2002 GMT+3 to GMT+4 Each time I was convinced I had found a better source. So who are we to believe? We have still not found any official russian page that gives the GMT offset explicitly. - Jesper Jesper Nørgaard Welen Email: jnorgard(a)Prodigy.Net.mx Project Leader (Líder de Proyecto) Software CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT Int. c/o Jesper Nørgaard Km. 45, Carretera México-Veracruz El Batán Texcoco, Edo. de México CP 56130 MEXICO Tel.: +52 (55) 58-04-20-04 ext. 1374 Fax: +52 (55) 58-04-75-58 Tel. Casa: 53-10-05-95 ó 53-10-97-78 Download the free program World Time Explorer, I made: http://www.worldtimeexplorer.com/index.html

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FW: Finnish summer time (DST) rule
by Olson, Arthur David (NIH/NCI) [E] May 15, 2006

May 15, 2006

Jukka A. Ukkonen is not on the time zone mailing list; direct replies appropriately. --ado -----Original Message----- From: Jukka A. Ukkonen [mailto:jau@iki.fi] Sent: Friday, May 12, 2006 1:57 AM To: tz(a)lecserver.nci.nih.gov Subject: Finnish summer time (DST) rule Greetings from Kirkkonummi (32km from Helsinki), The correct DST rule (in POSIX TZ syntax) for Finland has been at least since 2002 EET-02:00EEST-03:00,M3.5.0/03:00,M10.5.0/04:00 Notice that in there the zone change times are represented in the local time of the zone which is current at the moment when the change shall take place - i.e. both local times actually refer to 01:00 GMT. I guess Finland used this rule already several years before the common EU directive officially harmonized the DST rules all around EU from 2002 onwards. The EU directive can be found here... http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en002 10022.pdf I will let you know, if I find more precise info about when Finland actually adopted the current DST rule. Cheers, // jau .--- ..- -.- -.- .- .- .-.-.- ..- -.- -.- --- -. . -. / Jukka A. Ukkonen, Oxit Ltd, Finland /__ M.Sc. (sw-eng & cs) (Phone) +358-500-606-671 / Internet: Jukka.Ukkonen(a)Oxit.Fi (Home) +358-9-6215-280 / Internet: jau(a)iki.fi v .--- .- ..- ...-.- .. -.- .. .-.-.- ..-. .. + + + + My opinions are mine and mine alone, not my employers. + + + +

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Finnish summer time (DST) rule
by jau＠iki.fi May 12, 2006

May 12, 2006

Greetings from Kirkkonummi (32km from Helsinki), The correct DST rule (in POSIX TZ syntax) for Finland has been at least since 2002 EET-02:00EEST-03:00,M3.5.0/03:00,M10.5.0/04:00 Notice that in there the zone change times are represented in the local time of the zone which is current at the moment when the change shall take place - i.e. both local times actually refer to 01:00 GMT. I guess Finland used this rule already several years before the common EU directive officially harmonized the DST rules all around EU from 2002 onwards. The EU directive can be found here... http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en002100… I will let you know, if I find more precise info about when Finland actually adopted the current DST rule. Cheers, // jau .--- ..- -.- -.- .- .- .-.-.- ..- -.- -.- --- -. . -. / Jukka A. Ukkonen, Oxit Ltd, Finland /__ M.Sc. (sw-eng & cs) (Phone) +358-500-606-671 / Internet: Jukka.Ukkonen(a)Oxit.Fi (Home) +358-9-6215-280 / Internet: jau(a)iki.fi v .--- .- ..- ...-.- .. -.- .. .-.-.- ..-. .. + + + + My opinions are mine and mine alone, not my employers. + + + +

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Russia +4 breakout oblasts
by Jesper Norgaard Welen May 10, 2006

May 10, 2006

Oscar van Vlijmen made (as far as I understand) a thourough investigation of the Russian timezones in 2001-08-25 which documented all the oblasts that the russian timezones covers, listing the oblast's that correspond to each timezone. There are many english-speaking sites that to this day disagree with specific cities (stating that Kirov is on GMT+4 and similar), but after checking some russian sites I have come to the conclusion that the highly appreciated work of Oscar is still corresponding to current time in those places. However, all of the russian timezones in the tz database are declared as having been unaltered since 1991-1993 (this differs a bit from one russian timezone to the other), and especially the Europe/Samara timezone is unchanged since 1991 Oct 20 3:00. The following maps show the oblast' Kirovskaya, Saratovskaya, Volgogradskaya and Astrakhanskaya to be on GMT+4 as well: http://www.odci.gov/cia/publications/factbook/reference_maps/pdf/time_zones. pdf http://www.statoids.com/tru.html http://www.manifold.net/download/freemaps.html http://www.lib.utexas.edu/maps/world_maps/time_zone_world_98.jpg This is also true for a recent (1995+) ESRI map of timezones I have seen. The above links are all taken directly or indirectly from http://www.twinsun.com/tz/tz-link.htm Oscar is correct that since 2001 these were no longer on GMT+4 but had returned to GMT+3, but this return we have not documented with one or several timezones. I am not aware when these changes happened, but any guess would be better than the current state, where these four oblast' are on Moscow time since 1880, which is hardly likely to be true, if so many map makers have insisted on that they were on GMT+4 or even GMT+5. Regards, - Jesper Jesper Nørgaard Welen Email: jnorgard(a)Prodigy.Net.mx Project Leader (Líder de Proyecto) Software CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT Int. c/o Jesper Nørgaard Km. 45, Carretera México-Veracruz El Batán Texcoco, Edo. de México CP 56130 MEXICO Tel.: +52 (55) 58-04-20-04 ext. 1374 Fax: +52 (55) 58-04-75-58 Tel. Casa: 53-10-05-95 ó 53-10-97-78 Download the free program World Time Explorer, I made: http://www.worldtimeexplorer.com/index.html

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Bermuda will adopt US rules next year
by Paul Eggert May 8, 2006

May 8, 2006

In today's Royal Gazette, Stuart Roberts reports that Bermuda will fall into line with the US daylight-saving rules next year; see <http://www.theroyalgazette.com/apps/pbcs.dll/article?AID=/20060506/NEWS/105…>. Currently the tz tables take advantage of the fact that Bermuda and the Bahamas use the same DST rules, and have done so since 1974. My guess is that the Bahamas will fall into line as well, but I have no info about this, so perhaps it's better to play it safe for now and split these rules. There's no rush on this, since the new Bermuda rules don't affect time stamps until March 2007. Besides the Bahamas, other countries to watch on this front include Cuba, Haiti, Mexico, and Turks and Caicos.

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DST in Honduras, El Salvador, Guatemala, Nicaragua
by Jesper Norgaard Welen May 6, 2006

May 6, 2006

There is a flood of mutually conflicting stories on the near past/future DST changes in Honduras, El Salvador, Guatemala and Nicaragua. Here is a small bouquet of articles to consider, not that I will pretend to judge which are true or false: Change of DST in Honduras: http://ar.news.yahoo.com/060503/4/qmx7.html expected for this Sunday 7 at 0:00 Change of DST perhaps postponed in El Salvador: http://www.laprensagrafica.com/lodeldia/883.asp ... it has the interesting claim that Honduras changed the same time as Guatemala and Nicaragua. Change of DST in Guatemala: http://www.deguate.com/cgi-bin/noticias/print.pl?article=7134 claims that the return of DST will happen the 30.th. of September at 24 hours, or really 1.st. of October at 0:00. Another confirmation that Nicaragua change was at 2:00 in the morning: http://www.elnuevodiario.com.ni/2006/05/01/nacionales/18410: Por orden del presidente de la República, Enrique Bolaños, Nicaragua adelantó en sesenta minutos su hora oficial, ayer a las dos de la mañana, y así permanecerá hasta el 30 de septiembre. This means the following (my informal translation) By order of the president of the republic, Enrique Bolaños, Nicaragua advanced by sixty minutes their official time, yesterday at 2 in the morning, and will stay that way until 30.th. of september. Jesper Nørgaard Welen Email: jnorgard(a)Prodigy.Net.mx Project Leader (Líder de Proyecto) Software CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT Int. c/o Jesper Nørgaard Km. 45, Carretera México-Veracruz El Batán Texcoco, Edo. de México CP 56130 MEXICO Tel.: +52 (55) 58-04-20-04 ext. 1374 Fax: +52 (55) 58-04-75-58 Tel. Casa: 53-10-05-95 ó 53-10-97-78 Download the free program World Time Explorer, I made: http://www.worldtimeexplorer.com/index.html

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Honduras and El Salvador on DST too?
by Oscar van Vlijmen May 5, 2006

May 5, 2006

Reportedly (wordltimezone.com, some Spanish media) Honduras chose to follow Guatemala and will observe DST starting "la medianoche del sábado", so probably Saturday 06 May 2006, 24:00 local time. No ending date is mentioned other than "durante cuatro meses hasta septiembre" (during 4 months until September). My theory is: DST ends Saturday 02 September 2006 24:00 local time. El Salvador will follow Honduras. No serious details, no serious sources were given. I couldn't find any more reliable sources yet. Does anybody know more of this?

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Tzcode2006f.tar.gz and tzdata2006f.tar.gz
by Olson, Arthur David (NIH/NCI) [E] May 1, 2006

May 1, 2006

The files... ftp://elsie.nci.nih.gov/pub/tzcode2006f.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2006f.tar.gz ...are now available; a missing version number problem is fixed (with thanks to Bradley White for catching the problem). --ado

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Tzcode2006e.tar.gz and tzdata2006e.tar.gz
by Olson, Arthur David (NIH/NCI) [E] May 1, 2006

May 1, 2006

The files... ftp://elsie.nci.nih.gov/pub/tzcode2006e.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2006e.tar.gz ...are now available. These reflect the changes circulated on the time zone mailing list last week by Paul Eggert; I've also added new items to tz-arts.htm that were found by Paul. --ado

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RE: Some modifications of China related timezone info.
by Paul Schauble May 1, 2006

May 1, 2006

I agree with the drawbacks of using the most populated city as a proxy for a time zone. In this case, what's wrong with calling the tz zone Asia/China and being done with it? ++PLS -----Original Message----- From: tz-request(a)elsie.nci.nih.gov [mailto:tz-request@elsie.nci.nih.gov] On Behalf Of Zhe Su Sent: Saturday, April 29, 2006 7:06 AM To: Paul Eggert Cc: tz(a)lecserver.nci.nih.gov Subject: Re: Some modifications of China related timezone info. Hi, And in my opinion, using the rule of using most populous location to identify each region is not a generic way for every countries. IMO, we should use different rules for different countries to fit their local circumstances. For China (or more exactly, PRC), it's apparently not suitable to use the population rule. Because the most populous location in China is Chongqing, which is belong to Sichuan province, the most populous province of China. But Chongqing is far less developed than Shanghai and Beijing, so it's far less popular than Beijing and Shanghai. So for China, I'd prefer to use the most important and popular location, Beijing, the capital of China to identify our unique timezone. Regards James Su On 4/29/06, Zhe Su <james.su(a)gmail.com> wrote: > Hi, > I still can't agree with you. It's harmless to add "Asia/Beijing". > And China now uses only one timezone, which is called officially > "China Standard Time" and indeed it's known as Beijing Time. > Now we have five timezones for China in asia/zone.tab: > "Asia/Shanghai", "Asia/Chongqing", "Asia/Urumqi", "Asia/Harbin", > "Asia/Kashgar". But they are known as historic timezones (according to > comments in asia file). After 1949, the establishing of People's > Republic of China, we uses only one timezone, which is called "Beijing > Time" or "China Standard Time" officially. > So if you think we should choose a most populous city of China to > represent the only one "China Standard Time", that is Chongqing rather > than Shanghai, because Chongqing has more than 27 million population. > But, I still think using "Asia/Beijing" to represent the only timezone > used in Peoples Republic of China is the most reasonable way. > > Regards > James Su > > On 4/29/06, Paul Eggert <eggert(a)cs.ucla.edu> wrote: > > "Zhe Su" <james.su(a)gmail.com> writes: > > > > > So, is it ok to just add "Asia/Beijing" into the database along with > > > "Asia/Shanghai"? So that people can choose whatever they want. > > > > For now I'd rather not do that, for the reasons already mentioned. > > >

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Re: Some modifications of China related timezone info.
by Paul Eggert April 29, 2006

April 29, 2006

Ken Pizzini <tz.(a)explicate.org> writes: > the populations do seem to have converged significantly over the 15 > or so years since the Asia/Shanghai entry was created, and the trend > lines strongly suggest that if Beijing has not yet overtaken > Shanghai as the largest city in China, it is very likely to do so > soon. That depends on whose estimates one uses, and what one means by "soon". If we take estimates recently published by Chinese news agencies for the end of 2005, for example, Shanghai had 17.78 million people with a 2.030% annual growth rate since 2000 <http://english.sina.com/china/1/2006/0406/72038.html>, whereas Beijing had 15.36 million people with a 2.135% annual growth rate in the same period <http://news.xinhuanet.com/english/2006-04/20/content_4451085.htm>, so at current rates it will take about 142 years for Beijing's population to surpass Shanghai, at which point both cities will have populations of about 309 million people. To put it mildly, I don't have a lot of faith in these estimates, but until this thing settles out with a clear winner there's no rush. There is an advantage of keeping the Zone names stable, which our other correspondents have reminded us of periodically. I'd rather not get into the business of discussing zone names changes based on guesswork forecasts of population growth. (It's hard enough just keeping track of the clocks. :-)

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Re: Wisconsin's variation of CDT
by Larry M. Smith April 28, 2006

April 28, 2006

Paul Eggert wrote: > Robert Elz <kre(a)munnari.oz.au> writes: > >> Do you really believe that almost anyone (members of this list >> perhaps >> excepted) actually changes their clock at the precise instant that >> DST (or summer time, or whatever it gets called in different areas) >> actually changes. > > Yes, I do. Many people in this country no longer use watches; they > use cell phones to tell time. And cell phones did change at 02:00 in > Wisconsin on April 2; see > <http://www.wisbusiness.com/index.iml?Article=58272>. > <quote> At 2 a.m. on April 2, most of the United States turns clocks ahead one hour as Daylight Saving Time begins. The clock function on wireless phones is controlled by information in the signal from the network on which the phone is located. U.S. Cellular uses Global Positioning Satellite (GPS) technology to set the time on its network, transferring that information to customer handsets. At 2 a.m., the network adjusts the wireless handsetÆs clock for Daylight Saving Time automatically, making each phone an accurate reflection of the current local time. </quote> This argument is starting to recurse into itself; 1) If people in the state of Wisconsin tell time based on electronic equipment. 2) That equipment is keyed off of dataset that is incorrect for them. 3) That dataset should stay the way it is because this is how the people of Wisconsin tell time. Isn't this a circular argument? Please don't get me wrong... I am just publishing my finding, and I expect that before March of 2007 this will all be a moot point. When Wisconsin changes its law (as its dates will be wrong) I expect it will remove date and time and refer back to the U.S. law. So I expect these finding to be of historical nature by the time anyone outside of this list sees them. > I myself prefer an old-fashioned pocket watch, but I've observed that > my students, whose ages are typically around 20, use cell phones or > laptops to tell time just as often as they use watches -- perhaps even > more so. Sales of cheap watches reportedly declined 10% last year in > the US, most likely due to the popularity of telling time by cell > phone; see > <http://www.news-journalonline.com/NewsJournalOnline/News/Headlines/frtHEAD0…>. <quote> "Nowadays with all the electronic goods such as cell phones, iPods, the younger generation is more techno-savvy and they're relying upon electronics that they have and not wearing the watches." </quote> Again, using data based on tzdata. > > I imagine that people who have to log times (nurses, doctors, police > officers, and fire departments, for example) make sure their clocks > are close to the consensus time. These days no doubt a lot of this is > automated (mostly by our work, by Microsoft's, and by the cell phone > companies') but that still counts. > Again, based on tzdata. > I did consult some sources in Wisconsin for what people actually do, > and they agreed that 02:00 was the time people switched. See, for > example, > > Bob Petrie, Locals prepare to lose sleep, gain daylight, Sheboygan > Press (2006-04-01) > <http://www.htrnews.com/apps/pbcs.dll/article?AID=/20060401/SHE0101/60 > 4010508/1062> <quote> At 2 a.m. Sunday, Wisconsin makes the switch, which pushes sunset 60 minutes later into the evening. Sunday's sunset will be at 7:20 p.m. </quote> It can be argued that this reporter hadn't checked his facts. > > >> More likely to be relevant would be what time the radio stations >> announce during the "different" hour > > I'd be surprised if radio-station time announcements in Wisconsin > differed materially from the federal daylight-saving rules. > I have a number of phone calls out to different radio stations in regards to this, but it would not surprise me to find that they are using some device to track time and that it is linked back to using tzdata.

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RE: Some modifications of China related timezone info.
by Andy Lipscomb April 28, 2006

April 28, 2006

One other issue that may or may not be worth considering. Beijing mean time was, prior to the introduction of time zones, the standard for determining midnight in the computation of the Chinese calendar. Thus, having an entry with Beijing's mean time and transition point may be a help to programmers seeking to implement that calendar.

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Re: Some modifications of China related timezone info.
by Zhe Su April 28, 2006

April 28, 2006

Hi, So counting both kind of population, as Beijing and Shanghai have almost same amount of population (though Shanghai has slightly more population right now), and as Beijing is capital of China. I just suggest to add Asia/Beijing into timezone database along with Asia/Shanghai. Just like what was done in my proposed patch. Regards James Su On 4/28/06, Ken Pizzini <tz.(a)explicate.org> wrote: > On Fri, Apr 28, 2006 at 03:52:53PM +0800, Zhe Su wrote: > > I don't think we should count floating population, because those > > part of population is "floating", many of them will move around > > frequently. > > While _individuals_ in this category may come and go, in the aggregate > the "floating" population in these areas has been consistently and > continually growing. They are a real population. > The statistics I've seen (at least the ones that were of good > quality) only reported the *officially registered* portion of these > populations, so clearly the actual population of each urban > agglomeration is actually higher than typically reported, but I'm not > sure how this might affect the relative populations of Beijing and > Shanghai. > > > And the data source that you mentioned is apparently wrong. > > It's not that simple. The data sources I've been able to track down > are all over the map as to the absolute number associated with each > city. Part of this is just that they are reporting based on different > criteria: is the registered transient population included? > Is the unregistered transient population estimated? Is the census > just of the city proper, or does it include the entirety of the "urban > agglomeration"? How recently did the enumeration take place? > And what methodology was used to collect the information (official > census vs. statistical sampling, for example)? > > Except for the fact that it is five years out of date in a region of > very high demographic flux, the document that I would have trusted > most is the Fifth National Census (done in 2000-2001), which still > rated Shanghai more populous by a significant amount. > But clearly that isn't sufficient, so let's compare the value that you > quoted from a Dec. 2005 page on www.bj.xinhuanet.com with a page I > found from Jan. 2005 (in English): > > http://www.chinadaily.com.cn/english/doc/2005-01/10/content_407463.htm > If the two sets of values are presumed to both be correct, then that > means that Beijing's population grew by an astounding 10% over the > course of the year! (Almost all from immigration, since you also > quoted the 0.07% "natural" growth rate.) Surely there must be a > disagreement between how the National Population and Family Commission > of China (quoted by xinhuanet) and the Beijing Municipal Public > Security Bureau (quoted by chinadaily) do their counting. > This is the very kind of discrepancy that makes determining "the" > truth very challenging. > > > > So I suggest the following: the populations do seem to have converged > significantly over the 15 or so years since the Asia/Shanghai entry > was created, and the trend lines strongly suggest that if Beijing has > not yet overtaken Shanghai as the largest city in China, it is very > likely to do so soon. So I say that Asia/Beijing and Asia/Shanghai > should just be preemptively linked: we're talking concentrations of > over 15 million souls in each case anyway, which is surely significant > enough to be worth at least as much as the Africa/Timbuktu link? (As > to which is listed as primary and which as the link, I really don't > care. Toss a coin.) > > --Ken Pizzini >

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Re: Some modifications of China related timezone info.
by Ken Pizzini April 28, 2006

April 28, 2006

On Fri, Apr 28, 2006 at 03:52:53PM +0800, Zhe Su wrote: > I don't think we should count floating population, because those > part of population is "floating", many of them will move around > frequently. While _individuals_ in this category may come and go, in the aggregate the "floating" population in these areas has been consistently and continually growing. They are a real population. The statistics I've seen (at least the ones that were of good quality) only reported the *officially registered* portion of these populations, so clearly the actual population of each urban agglomeration is actually higher than typically reported, but I'm not sure how this might affect the relative populations of Beijing and Shanghai. > And the data source that you mentioned is apparently wrong. It's not that simple. The data sources I've been able to track down are all over the map as to the absolute number associated with each city. Part of this is just that they are reporting based on different criteria: is the registered transient population included? Is the unregistered transient population estimated? Is the census just of the city proper, or does it include the entirety of the "urban agglomeration"? How recently did the enumeration take place? And what methodology was used to collect the information (official census vs. statistical sampling, for example)? Except for the fact that it is five years out of date in a region of very high demographic flux, the document that I would have trusted most is the Fifth National Census (done in 2000-2001), which still rated Shanghai more populous by a significant amount. But clearly that isn't sufficient, so let's compare the value that you quoted from a Dec. 2005 page on www.bj.xinhuanet.com with a page I found from Jan. 2005 (in English): http://www.chinadaily.com.cn/english/doc/2005-01/10/content_407463.htm If the two sets of values are presumed to both be correct, then that means that Beijing's population grew by an astounding 10% over the course of the year! (Almost all from immigration, since you also quoted the 0.07% "natural" growth rate.) Surely there must be a disagreement between how the National Population and Family Commission of China (quoted by xinhuanet) and the Beijing Municipal Public Security Bureau (quoted by chinadaily) do their counting. This is the very kind of discrepancy that makes determining "the" truth very challenging. So I suggest the following: the populations do seem to have converged significantly over the 15 or so years since the Asia/Shanghai entry was created, and the trend lines strongly suggest that if Beijing has not yet overtaken Shanghai as the largest city in China, it is very likely to do so soon. So I say that Asia/Beijing and Asia/Shanghai should just be preemptively linked: we're talking concentrations of over 15 million souls in each case anyway, which is surely significant enough to be worth at least as much as the Africa/Timbuktu link? (As to which is listed as primary and which as the link, I really don't care. Toss a coin.) --Ken Pizzini

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Re: Some modifications of China related timezone info.
by Zhe Su April 28, 2006

April 28, 2006

Hi, I don't think we should count floating population, because those part of population is "floating", many of them will move around frequently. And the data source that you mentioned is apparently wrong. Regards James Su On 4/28/06, Paul Eggert <eggert(a)cs.ucla.edu> wrote: > Robert Elz <kre(a)munnari.oz.au> writes: > > > Having a simple rule that always gets followed allows us to ignore > > endless arguments > > Yes, that's one of the principal motivations. > > > Of course, if it is a close thing, and it is possible that Shanghai > > may overtake Beijing again next year (or something) then keeping > > switching backwards and forwards would be irrational > > Yes, in the past when this has happened, we've tried to avoid change > for the sake of tracking the current ephemeral champion. Of course > this has to be done within reason; if the new champion is undisputed > then it would be time to change. > > But as far as Beijing vs Shanghai goes, it seems that the current > headcount leader is still Shanghai, if we include the floating > population and use the statistics James Su mentioned. > > Also, if we count the entire metropolitan-area population, the > statistics I've seen suggest that Beijing still trails well behind > Shanghai. See <http://www.citypopulation.de/World.html>, for example, > which gives 12.1 million for Beijing and 18.2 million for Shanghai. > Or > <http://www.world-gazetteer.com/wg.php?men=gcis&dat=32&geo=-54&srt=pna > n&col=aohdq&pt=a&srt=pnan>, which gives 11.5 million for Beijing and > 14.9 million for Shanghai. >

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Re: Some modifications of China related timezone info.
by Paul Eggert April 28, 2006

April 28, 2006

Robert Elz <kre(a)munnari.oz.au> writes: > Having a simple rule that always gets followed allows us to ignore > endless arguments Yes, that's one of the principal motivations. > Of course, if it is a close thing, and it is possible that Shanghai > may overtake Beijing again next year (or something) then keeping > switching backwards and forwards would be irrational Yes, in the past when this has happened, we've tried to avoid change for the sake of tracking the current ephemeral champion. Of course this has to be done within reason; if the new champion is undisputed then it would be time to change. But as far as Beijing vs Shanghai goes, it seems that the current headcount leader is still Shanghai, if we include the floating population and use the statistics James Su mentioned. Also, if we count the entire metropolitan-area population, the statistics I've seen suggest that Beijing still trails well behind Shanghai. See <http://www.citypopulation.de/World.html>, for example, which gives 12.1 million for Beijing and 18.2 million for Shanghai. Or <http://www.world-gazetteer.com/wg.php?men=gcis&dat=32&geo=-54&srt=pnan&col=…>, which gives 11.5 million for Beijing and 14.9 million for Shanghai.

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Saskatchewan (2007)
by Chris Walton April 28, 2006

April 28, 2006

Over the past couple of months I have posted a number of e-mails related to Canadian time legislation. I never mentioned Saskatchewan because most of the province does not observe daylight saving time. There are actually two small regions in Saskatchewan that do use daylight saving time: 1)Lloydminster and surrounding area. 2)Creighton and Denare Beach area. Both of these regions are briefly mentioned in TZDATA's "northamerica" file. ################# The city of Lloydminster straddles the Alberta/Saskatchewan border. It uses MST/MDT. There is a special bit of legislation called the "Lloydminster Charter". The bylaws in the charter cover the entire city (both sides of the provincial border). Here are two URLs for the charter. Government of Alberta web site: http://www.qp.gov.ab.ca/Documents/REGS/1979_043.CFM Government of Saskatchewan web site: http://www.qp.gov.sk.ca/documents/english/Statutes/Historical/lloydchr.pdf Section 5(2) reads: ------------------------------------------------------------------ "Whenever any particular time of day is referred to in this Charter, the same shall mean Mountain Standard Time except that in every year during the period between two o'clock in the forenoon of the first Sunday in April and two o'clock in the forenoon of the last Sunday in October it shall mean Central Standard Time." ----------------------------------------------------------------- Since Lloydminster has traditionally followed the daylight savings practices of Alberta, I assume that the charter will have to be updated for 2007. ################# The Battle River region surrounding the city of Lloydminster uses the same time as Lloydminster. Presumably the bylaws in the Lloydminster Charter don't apply outside the city limits. So the region surrounding Lloydminster on the east side of the provincial border is subject to the rules in the Saskatchewan Time Act. The Saskatchewan Time Act defines time for all regions of the province except the city of Lloydminster. The Act allows the rules in western parts of the province to be overridden by public election. http://www.qp.gov.sk.ca/documents/english/statutes/statutes/t14.pdf Several sections of the act are of interest: ---------------------------------------------------------------- 2(i) "summer period means that period in each year beginning at two o'clock, mountain standard time, in the forenoon of the first Sunday in April and ending at two o'clock, mountain standard time, in the forenoon of the last Sunday in October;" --------------------------------------------------------------- "Non-application of Act 5 Nothing in this Act applies to a reference to time in: (a) The Lloydminster Charter; or"... --------------------------------------------------------------- "Time in certain areas of western Saskatchewan 8(1) The time to be used and observed in western Saskatchewan: (a) during the summer period, is central standard time; and (b) during the winter period, is mountain standard time, except in respect of any time option area where central standard time is decided upon by a majority of the electors of the time option area voting with respect thereto under this Act whose ballots are not rejected. (2) Notwithstanding subsection (1), on and from the commencement of the winter period in 1983 and until a vote is taken in accordance with this Act, the time to be used and observed: (a) in the Battle River Time Option Area: (i) during the summer period, is central standard time; and (ii) during the winter period, is mountain standard time; and (b) throughout the year in the Paynton Time Option Area is central standard time." --------------------------------------------------------------------- Notice that the transition from daylight time to standard time is supposed to take place at 2:00am MST (3:00MDT). This is one hour after the transition defined in the Lloydminster charter. Therefore, the area surrounding Lloydminster on the east side of the provincial border should be out of sync with Lloydminster for one hour each year. Ugh! Doesn't this call for a new time zone for a region that probably has no more than 2 or 3 thousand residents. Maybe we just have to ignore the Time Act. The NRC seems to have ignored it. The INMS-NRC site says: "Areas around Lloydminster are in the Mountain Time zone and change at 2:00a.m. local time as in Alberta" http://inms-ienm.nrc-cnrc.gc.ca/en/faq_time_e.php#5 ################ And finally there is the small area that contains the towns of Creighton and Denare Beach. This region uses CST/CDT to align with the city of Flin Flon Manitoba. The use of daylight saving time in this region is in defiance of the Saskatchewan Time Act. Should we stop and ponder what time Creighton and Denare Beach have historically done the transition from daylight time to standard time? Is it: a) 2:00am wall time as is tradition in most parts of the country or b) 02:00 CST (3:00am wall time) as per the old Manitoba Time Act or c) 02:00 MST (4:00am wall time) as per the definition of "summer time" in the Saskatchewan Time Act? or d) 8:07am wall time because we can't expect non-law-abiding citizens get up in the middle of the night to change the clocks. It will be interesting to see if the Saskatchewan government bothers to update the Time Act to reflect the extra four weeks of daylight savings in 2007. Personally I think that the all fourteen pages of the old act should be burned and replaced with something more concise. But that is just my opinion. I will keep an eye out for new legislation and I will post an e-mail to this group if I see anything. -chris

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Re: Wisconsin's variation of CDT
by Paul Eggert April 28, 2006

April 28, 2006

Robert Elz <kre(a)munnari.oz.au> writes: > Do you really believe that almost anyone (members of this list perhaps > excepted) actually changes their clock at the precise instant that DST > (or summer time, or whatever it gets called in different areas) > actually changes. Yes, I do. Many people in this country no longer use watches; they use cell phones to tell time. And cell phones did change at 02:00 in Wisconsin on April 2; see <http://www.wisbusiness.com/index.iml?Article=58272>. I myself prefer an old-fashioned pocket watch, but I've observed that my students, whose ages are typically around 20, use cell phones or laptops to tell time just as often as they use watches -- perhaps even more so. Sales of cheap watches reportedly declined 10% last year in the US, most likely due to the popularity of telling time by cell phone; see <http://www.news-journalonline.com/NewsJournalOnline/News/Headlines/frtHEAD0…>. I imagine that people who have to log times (nurses, doctors, police officers, and fire departments, for example) make sure their clocks are close to the consensus time. These days no doubt a lot of this is automated (mostly by our work, by Microsoft's, and by the cell phone companies') but that still counts. I did consult some sources in Wisconsin for what people actually do, and they agreed that 02:00 was the time people switched. See, for example, Bob Petrie, Locals prepare to lose sleep, gain daylight, Sheboygan Press (2006-04-01) <http://www.htrnews.com/apps/pbcs.dll/article?AID=/20060401/SHE0101/60401050…> > More likely to be relevant would be what time the radio stations > announce during the "different" hour I'd be surprised if radio-station time announcements in Wisconsin differed materially from the federal daylight-saving rules.

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Re: Some modifications of China related timezone info.
by Zhe Su April 28, 2006

April 28, 2006

Hi, As I mentioned, according to the data of 2005, the resident population of Beijing is about 13.8 million, Shanghai is about 13.4 million. The natural growth rate of Beijing resident population is about 0.1% (2005 is 0.07%), (data from http://www.bj.xinhuanet.com/bjpd_sdzx/2005-12/06/content_5751145.htm) While, the natural growth rate of Shanghai resident population is -0.03% (2005) and has been kept nagative for 8 years. (data from http://www.happyhome.net.cn/read.asp?subjectid=212&infoid=1452&forumid=14117) Though, the growth rate of floating population of both cities are very high. More and more people come to Beijing and Shanghai from other provinces for work. Regards James Su On 4/28/06, Robert Elz <kre(a)munnari.oz.au> wrote: > Date: Fri, 28 Apr 2006 13:02:16 +0800 > From: "Zhe Su" <james.su(a)gmail.com> > Message-ID: > <278a3d0604272202t58aa5802nf0b11c63bfe110bb(a)mail.gmail.com> > > | Following this rule, "Asia/Beijing" should be used instead of > | "Asia/Shanghai", because more people prefer "Asia/Beijing" in China, > | as Beijing has more people than Shanghai :-) > > If the population of Beijing is greater than that of Shanghai then > you're right, the zone name should be changed (with the old one left > as an alias for a while for people who are used to it). It would > not be the first time that names have changed for this reason (when > relative populations of different cities alters). > > Of course, if it is a close thing, and it is possible that Shanghai > may overtake Beijing again next year (or something) then keeping > switching backwards and forwards would be irrational - so just keeping > things stable should be better, but if (which I would certainly > imagine is possible) that Beijing is simply growing faster than > Shanghai and has now grown bigger, the zone name can change. > > kre >

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Re: Some modifications of China related timezone info.
by Robert Elz April 28, 2006

April 28, 2006

Date: Fri, 28 Apr 2006 13:02:16 +0800 From: "Zhe Su" <james.su(a)gmail.com> Message-ID: <278a3d0604272202t58aa5802nf0b11c63bfe110bb(a)mail.gmail.com> | Following this rule, "Asia/Beijing" should be used instead of | "Asia/Shanghai", because more people prefer "Asia/Beijing" in China, | as Beijing has more people than Shanghai :-) If the population of Beijing is greater than that of Shanghai then you're right, the zone name should be changed (with the old one left as an alias for a while for people who are used to it). It would not be the first time that names have changed for this reason (when relative populations of different cities alters). Of course, if it is a close thing, and it is possible that Shanghai may overtake Beijing again next year (or something) then keeping switching backwards and forwards would be irrational - so just keeping things stable should be better, but if (which I would certainly imagine is possible) that Beijing is simply growing faster than Shanghai and has now grown bigger, the zone name can change. kre

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Re: Some modifications of China related timezone info.
by Zhe Su April 28, 2006

April 28, 2006

Hi, That's not true. According the data from "National Population and Family Commission of China", last year, Shanghai has 13.4 million resident population, while Beijing has 13.8 million resident population. At the same time, Shanghai has about 5.8 floating population, Beijing has about 3 million floating population. So, Beijing has more resident population than Shanghai, though the total population is less. The data from: Shanghai: http://www.chinapop.gov.cn/rkxx/rkxw/t20060406_58076.htm Beijing: http://www.gjjsw.gov.cn/rkzh/zgrk/tjgb/t20040326_2833.htm (Sorry, they are in Chinese) Both for 2005 year. Regards James Su On 4/28/06, David Keegel <djk(a)cybersource.com.au> wrote: > My research on google suggests Beijing is about 15 million population, > and Shanghai is about 18-20 million. > > On Fri, Apr 28, 2006 at 01:02:16PM +0800, Zhe Su wrote: > > Hi, > > Following this rule, "Asia/Beijing" should be used instead of > > "Asia/Shanghai", because more people prefer "Asia/Beijing" in China, > > as Beijing has more people than Shanghai :-) > > > > Regards > > James Su > > -- > ______________________________________________________________________ > _____ David Keegel <djk(a)cybersource.com.au> > http://www.cyber.com.au/users/djk/ > Cybersource P/L: Linux/Unix Systems Administration > Consulting/Contracting >

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