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Is there a list of "current" time zones?
by Tim Klein July 11, 2007

July 11, 2007

I'm new here. As I look through the tz database, and the archives of this mailing list, I realize what a phenomenal effort you folks have put in, to make all of this information available. Thank you for all you've done! A question... I'm helping to write an application that needs a menu for the user to choose what time zone they live in. With ~400 time zones in the database, that'd be a pretty daunting pull-down menu. But as I understand it, a significant fraction of the ~400 time zones exist only for historical reasons. Since our application will deal only with current and future times, historical distinctions don't matter, and we'd like the menu to show only the subset of time zones that are currently "in effect". (And we don't mind if it isn't painstakingly accurate or updated in real time.) Has anyone created such a list? Or maybe an algorithm (if not code) for generating one from the full database? I see that this question has come up in the past. To quote from the archives... ====== >From: "Andy Lipscomb" <AndyLipscomb(a)decosimo.com> >Perhaps a better term would be "historical" time zones. This would >in fact be a useful distinction, since only a relatively small >subset of the timezones are necessary for applications that look >only forward--these would be the first set to present to a user for >selecting a time zone, with a "show all" option to get the complete >list. (For example, the 50 United States can be covered on a >forward-looking basis by eight zones--New York, Chicago, Denver, >Phoenix, Los Angeles, Anchorage, Adak, and Honolulu. And if one >takes as irrevocable the power of the EU over DST dates, then--for >example--London, Paris, and Helsinki would cover that entire area, >except for the different abbreviations used in the three +0 >countries.) ====== And... >From: Paul Eggert [mailto:eggert@CS.UCLA.EDU] >Sent: November 6, 2006 12:13 PM > >> Is there any way to flag some of the old historical zones such that >> they don't appear when running "tzselect"? > >We could have a table for people who don't care about historical >times, which maps zone names to "modern" zone names, and tzselect >could have an option to use that table. ====== Thank you very much for any wisdom on this subject! Tim Klein Dallas, Texas, USA

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FW: Time Zone mapping --> Windows ???
by Olson, Arthur David (NIH/NCI) [E] July 11, 2007

July 11, 2007

I'm forwarding this message from Boris Lang, 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 -----Original Message----- From: BORIS LANG [mailto:BORIS.LANG@MEMO.IKEA.COM] Sent: Tuesday, July 10, 2007 8:55 AM To: tz(a)lecserver.nci.nih.gov Subject: Time Zone mapping --> Windows ??? --- Received from IKEA4.BRLG +49 6122 5858276 07-07-10 14.56 -------------------------------------- Hi, we are working on the implementation of time zone information into an application using the tz database. TZ data names will be our main type but we also need to do a mapping to the time zone names used in windows. i.e. Europe/Berlin (tzd) --> Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna (Windows) The problem is that I can´t find a complete list that contains the mapping from tz database to windows. Can somebody please help us? Is there already such a list existing? Best regards Boris Lang ------ IKEA IT Germany GmbH Am Wandersmann 2-4 65719 Hofheim-Wallau Sitz München HR B 79392, Amtsgericht München Geschäftsführer: Manfred Godlewski, Göran Sjöstrand, Ola Troedsson ---- 07-07-10 14.56 ---- Sent to --------------------------------------------------------------------------------- -> tz(a)elsie.nci.nih.gov

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Re: FW: Localization of timezones from zone.tab
by Mark Davis July 10, 2007

July 10, 2007

There is a users group at http://www.unicode.org/consortium/distlist.html#cldr_list. You can post suggestions/requests via the bug form on http://www.unicode.org/cldr/bugs/locale-bugs. If you belong to a Unicode member organization (http://www.unicode.org/consortium/memblogo.html) you can get on the internal list and even (if you choose) the weekly teleconference. Mark On 7/10/07, Chuck Soper <chucks2(a)veladg.com> wrote: > > Thanks for your response. I now remember meeting someone from IBM at an > IMUG meeting at Apple; he described metazones. > > What is the best way for me to stay informed of CLDR related to time > zones? And is there a way to make comments, suggestions or discuss? > > Chuck > > At 1:54 PM -0700 7/10/07, Mark Davis wrote: > > We have actually instituted an alternative mechanism called 'metazones', > which are somewhat like what you describe. They basically coalesce zones > that have the same behavior in modern time. However, they have some further > restrictions, and we only put this in recently thus haven't gathered enough > data to be useful yet. > > Mark > > On 7/10/07,* Chuck Soper* <chucks2(a)veladg.com> wrote: > > I've been on the tz list for several years. I have tried to follow the > Time Zone Localizations topic for CLDR. > > > I do not understand why translations would be supplied for timezone IDs > (tzIDs). Many tzIDs refer to the same time zone name. For example, I believe > that Argentina has 2 time zone names, yet it has 10 tzIDs to handle DST > rules for various states. Does this mean that 20 localized names would be > required for Argentina? Does this mean that a new tzID would not be > localized? > > > Looking at 381 tzIDs of a tzData version (from 2006), I multiply it by two > (for std and dst names) to obtain 762 time zone names required. By removing > names of tzIDs that do not recognize DST and removing tzIDs that refer to > the same time name (e.g. many tzIDs refer to Central European Time), I was > to reduce total time zone names from 762 to 212. > > > Can over 500 names can be removed from the translation list? Multiplying > 500 potentially unneeded names by the number of translations would result in > a large reduction of translation efforts. > > > My approach is dependent on having a stable list of time zone names. As > far as I know, such a list does not exist. If such a list existed, I would > envision tzIDs being mapped to the 'time zone name' list. > > > Chuck > > > > At 10:44 AM -0700 7/10/07, Mark Davis wrote: > > The Unicode CLDR project (http://unicode.org/cldr/) does supply > translations for timezone IDs. There are a few caveats. > > 1. The timezone database really has equivalence classes of IDs. One > of these can be used as a representative for any in the equivalence class. > It is the zone.tab file that contains such IDs. CLDR started by using that > file, but unfortunately it is not stable (different equivalent IDs can be > substituted at any time). So what we do is use as the representative the one > that historically the first one used in any zone.tab file (after CLDR > started). > > 2. We allow, but do not encourage, translation of zones that are the > only zone in a country. For that we use the country name. This cuts down > very substantially on the number of translations needed. That is, you would > see the equivalent of "Italy", and "United States (Los Angeles)" -- only in > the latter case do we need translations for the cities. > > 3. Translators can optionally add other variations: daylight (summer) > time, standard (winter) time, and generic time, both abbreviated and long. > > 4. These choices percolate out to clients of CLDR: Google, IBM, > Apple, Adobe, and many others. > > Mark > > On 7/10/07,* Olson, Arthur David (NIH/NCI) [E]* <olsona(a)dc37a.nci.nih.gov> > wrote: > > I'm forwarding this message from Vincent Untz, 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 > > -----Original Message----- > From: Vincent Untz [mailto: vuntz(a)gnome.org] > Sent: Tuesday, July 10, 2007 1:24 PM > To: tz(a)lecserver.nci.nih.gov > Subject: Localization of timezones from zone.tab > > Hi, > > [please keep me cc'ed since I'm not subscribed to this list] > > I know that, at least in GNOME, there are now three places where we > > parse zone.tab to get a list of timezones supported by the OS. I suppose > other projects are also doing this. This list is then presented to the > user to let him choose the timezone. > > The problem here is that we let the user choose strings which look like > "Antarctica/South_Pole". This is not really good for > non-english-speaking people ;-) > > Of course, we can add all the timezones to our list of strings to > translate, but this means all projects needing to do so will duplicate > this work and the translations. > > I'd like the tz database to ship translations in po files. This would > imply the following: > > + create a small script to generate a POT file from zone.tab (easy) > + submit the POT file to the translation project [1] (or any other > > place that helps with translation) > > + add the po files for translation to the tz database > + choose a gettext domain > > (Of course, I'm quite probably forgetting about a step :-)) > > I've seen that this topic has been discussed before [2], but the > proposition there was really more ambitious, so I'm hoping a simple > approach would be welcomed. > > What do you think? > > Thanks, > > [1] http://translationproject.org/ > [2] http://osdir.com/ml/time.tz/2004-09/msg00000.html > > Vincent > > -- > Les gens heureux ne sont pas pressés. > > > > > -- > Mark > > > > > > -- > Mark > > > -- Mark

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Re: FW: Localization of timezones from zone.tab
by Mark Davis July 10, 2007

July 10, 2007

We have actually instituted an alternative mechanism called 'metazones', which are somewhat like what you describe. They basically coalesce zones that have the same behavior in modern time. However, they have some further restrictions, and we only put this in recently thus haven't gathered enough data to be useful yet. Mark On 7/10/07, Chuck Soper <chucks2(a)veladg.com> wrote: > > I've been on the tz list for several years. I have tried to follow the > Time Zone Localizations topic for CLDR. > > I do not understand why translations would be supplied for timezone IDs > (tzIDs). Many tzIDs refer to the same time zone name. For example, I believe > that Argentina has 2 time zone names, yet it has 10 tzIDs to handle DST > rules for various states. Does this mean that 20 localized names would be > required for Argentina? Does this mean that a new tzID would not be > localized? > > Looking at 381 tzIDs of a tzData version (from 2006), I multiply it by two > (for std and dst names) to obtain 762 time zone names required. By removing > names of tzIDs that do not recognize DST and removing tzIDs that refer to > the same time name (e.g. many tzIDs refer to Central European Time), I was > to reduce total time zone names from 762 to 212. > > Can over 500 names can be removed from the translation list? Multiplying > 500 potentially unneeded names by the number of translations would result in > a large reduction of translation efforts. > > My approach is dependent on having a stable list of time zone names. As > far as I know, such a list does not exist. If such a list existed, I would > envision tzIDs being mapped to the 'time zone name' list. > > Chuck > > > At 10:44 AM -0700 7/10/07, Mark Davis wrote: > > The Unicode CLDR project (http://unicode.org/cldr/) does supply > translations for timezone IDs. There are a few caveats. > > 1. The timezone database really has equivalence classes of IDs. One > of these can be used as a representative for any in the equivalence class. > It is the zone.tab file that contains such IDs. CLDR started by using that > file, but unfortunately it is not stable (different equivalent IDs can be > substituted at any time). So what we do is use as the representative the one > that historically the first one used in any zone.tab file (after CLDR > started). > > 2. We allow, but do not encourage, translation of zones that are the > only zone in a country. For that we use the country name. This cuts down > very substantially on the number of translations needed. That is, you would > see the equivalent of "Italy", and "United States (Los Angeles)" -- only in > the latter case do we need translations for the cities. > > 3. Translators can optionally add other variations: daylight (summer) > time, standard (winter) time, and generic time, both abbreviated and long. > > 4. These choices percolate out to clients of CLDR: Google, IBM, > Apple, Adobe, and many others. > > Mark > > On 7/10/07,* Olson, Arthur David (NIH/NCI) [E]* <olsona(a)dc37a.nci.nih.gov> > wrote: > > I'm forwarding this message from Vincent Untz, 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 > > -----Original Message----- > From: Vincent Untz [mailto: vuntz(a)gnome.org] > Sent: Tuesday, July 10, 2007 1:24 PM > To: tz(a)lecserver.nci.nih.gov > Subject: Localization of timezones from zone.tab > > Hi, > > [please keep me cc'ed since I'm not subscribed to this list] > > I know that, at least in GNOME, there are now three places where we > parse zone.tab to get a list of timezones supported by the OS. I suppose > other projects are also doing this. This list is then presented to the > user to let him choose the timezone. > > The problem here is that we let the user choose strings which look like > "Antarctica/South_Pole". This is not really good for > non-english-speaking people ;-) > > Of course, we can add all the timezones to our list of strings to > translate, but this means all projects needing to do so will duplicate > this work and the translations. > > I'd like the tz database to ship translations in po files. This would > imply the following: > > + create a small script to generate a POT file from zone.tab (easy) > + submit the POT file to the translation project [1] (or any other > > place that helps with translation) > > + add the po files for translation to the tz database > + choose a gettext domain > > (Of course, I'm quite probably forgetting about a step :-)) > > I've seen that this topic has been discussed before [2], but the > proposition there was really more ambitious, so I'm hoping a simple > approach would be welcomed. > > What do you think? > > Thanks, > > [1] http://translationproject.org/ > [2] http://osdir.com/ml/time.tz/2004-09/msg00000.html > > Vincent > > -- > Les gens heureux ne sont pas pressés. > > > > > -- > Mark > > > -- Mark

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Re: FW: Localization of timezones from zone.tab
by Chuck Soper July 10, 2007

July 10, 2007

I've been on the tz list for several years. I have tried to follow the Time Zone Localizations topic for CLDR. I do not understand why translations would be supplied for timezone IDs (tzIDs). Many tzIDs refer to the same time zone name. For example, I believe that Argentina has 2 time zone names, yet it has 10 tzIDs to handle DST rules for various states. Does this mean that 20 localized names would be required for Argentina? Does this mean that a new tzID would not be localized? Looking at 381 tzIDs of a tzData version (from 2006), I multiply it by two (for std and dst names) to obtain 762 time zone names required. By removing names of tzIDs that do not recognize DST and removing tzIDs that refer to the same time name (e.g. many tzIDs refer to Central European Time), I was to reduce total time zone names from 762 to 212. Can over 500 names can be removed from the translation list? Multiplying 500 potentially unneeded names by the number of translations would result in a large reduction of translation efforts. My approach is dependent on having a stable list of time zone names. As far as I know, such a list does not exist. If such a list existed, I would envision tzIDs being mapped to the 'time zone name' list. Chuck At 10:44 AM -0700 7/10/07, Mark Davis wrote: >The Unicode CLDR project >(<http://unicode.org/cldr/>http://unicode.org/cldr/) >does supply translations for timezone IDs. There >are a few caveats. > >1. The timezone database really has >equivalence classes of IDs. One of these can be >used as a representative for any in the >equivalence class. It is the zone.tab file that >contains such IDs. CLDR started by using that >file, but unfortunately it is not stable >(different equivalent IDs can be substituted at >any time). So what we do is use as the >representative the one that historically the >first one used in any zone.tab file (after CLDR >started). >2. We allow, but do not encourage, >translation of zones that are the only zone in a >country. For that we use the country name. This >cuts down very substantially on the number of >translations needed. That is, you would see the >equivalent of "Italy", and "United States (Los >Angeles)" -- only in the latter case do we need >translations for the cities. >3. Translators can optionally add other >variations: daylight (summer) time, standard >(winter) time, and generic time, both >abbreviated and long. >4. These choices percolate out to clients of >CLDR: Google, IBM, Apple, Adobe, and many others. > >Mark > >On 7/10/07, Olson, Arthur David (NIH/NCI) [E] ><<mailto:olsona@dc37a.nci.nih.gov>olsona(a)dc37a.nci.nih.gov> >wrote: > >I'm forwarding this message from Vincent Untz, >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 > >-----Original Message----- >From: Vincent Untz [mailto:<mailto:vuntz@gnome.org> vuntz(a)gnome.org] >Sent: Tuesday, July 10, 2007 1:24 PM >To: <mailto:tz@lecserver.nci.nih.gov>tz(a)lecserver.nci.nih.gov >Subject: Localization of timezones from zone.tab > >Hi, > >[please keep me cc'ed since I'm not subscribed to this list] > >I know that, at least in GNOME, there are now three places where we >parse zone.tab to get a list of timezones supported by the OS. I suppose >other projects are also doing this. This list is then presented to the >user to let him choose the timezone. > >The problem here is that we let the user choose strings which look like >"Antarctica/South_Pole". This is not really good for >non-english-speaking people ;-) > >Of course, we can add all the timezones to our list of strings to >translate, but this means all projects needing to do so will duplicate >this work and the translations. > >I'd like the tz database to ship translations in po files. This would >imply the following: > >+ create a small script to generate a POT file from zone.tab (easy) >+ submit the POT file to the translation project [1] (or any other > place that helps with translation) >+ add the po files for translation to the tz database >+ choose a gettext domain > >(Of course, I'm quite probably forgetting about a step :-)) > >I've seen that this topic has been discussed before [2], but the >proposition there was really more ambitious, so I'm hoping a simple >approach would be welcomed. > >What do you think? > >Thanks, > >[1] <http://translationproject.org/>http://translationproject.org/ >[2] ><http://osdir.com/ml/time.tz/2004-09/msg00000.html> >http://osdir.com/ml/time.tz/2004-09/msg00000.html > >Vincent > >-- >Les gens heureux ne sont pas pressés. > > > > >-- >Mark

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Localization of timezones from zone.tab
by Vincent Untz July 10, 2007

July 10, 2007

Hi, [please keep me cc'ed since I'm not subscribed to this list] I know that, at least in GNOME, there are now three places where we parse zone.tab to get a list of timezones supported by the OS. I suppose other projects are also doing this. This list is then presented to the user to let him choose the timezone. The problem here is that we let the user choose strings which look like "Antarctica/South_Pole". This is not really good for non-english-speaking people ;-) Of course, we can add all the timezones to our list of strings to translate, but this means all projects needing to do so will duplicate this work and the translations. I'd like the tz database to ship translations in po files. This would imply the following: + create a small script to generate a POT file from zone.tab (easy) + submit the POT file to the translation project [1] (or any other place that helps with translation) + add the po files for translation to the tz database + choose a gettext domain (Of course, I'm quite probably forgetting about a step :-)) I've seen that this topic has been discussed before [2], but the proposition there was really more ambitious, so I'm hoping a simple approach would be welcomed. What do you think? Thanks, [1] http://translationproject.org/ [2] http://osdir.com/ml/time.tz/2004-09/msg00000.html Vincent -- Les gens heureux ne sont pas pressés.

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Re: Is there a list of "current" time zones?
by Philip Howell July 10, 2007

July 10, 2007

Hi Tim, In the tzdata tarball is a file called zone.tab. It lists the current time zones grouped by country code. Cheers, Phil Tim Klein wrote: > I'm new here. As I look through the tz database, and the archives of > this mailing list, I realize what a phenomenal effort you folks have > put in, to make all of this information available. Thank you for all > you've done! > > A question... > > I'm helping to write an application that needs a menu for the user to > choose what time zone they live in. With ~400 time zones in the > database, that'd be a pretty daunting pull-down menu. > > But as I understand it, a significant fraction of the ~400 time zones > exist only for historical reasons. Since our application will deal > only with current and future times, historical distinctions don't > matter, and we'd like the menu to show only the subset of time zones > that are currently "in effect". (And we don't mind if it isn't > painstakingly accurate or updated in real time.) > > Has anyone created such a list? Or maybe an algorithm (if not code) > for generating one from the full database? > > I see that this question has come up in the past. To quote from the > archives... > > ====== > >> From: "Andy Lipscomb" <AndyLipscomb(a)decosimo.com> >> Perhaps a better term would be "historical" time zones. This would in >> fact be a useful distinction, since only a relatively small subset of >> the timezones are necessary for applications that look only >> forward--these would be the first set to present to a user for >> selecting a time zone, with a "show all" option to get the complete >> list. (For example, the 50 United States can be covered on a >> forward-looking basis by eight zones--New York, Chicago, Denver, >> Phoenix, Los Angeles, Anchorage, Adak, and Honolulu. And if one takes >> as irrevocable the power of the EU over DST dates, then--for >> example--London, Paris, and Helsinki would cover that entire area, >> except for the different abbreviations used in the three +0 countries.) > > ====== > And... > >> From: Paul Eggert [mailto:eggert@CS.UCLA.EDU] >> Sent: November 6, 2006 12:13 PM >> >>> Is there any way to flag some of the old historical zones such that >>> they don't appear when running "tzselect"? >> >> We could have a table for people who don't care about historical >> times, which maps zone names to "modern" zone names, and tzselect >> could have an option to use that table. > > ====== > > Thank you very much for any wisdom on this subject! > > Tim Klein > Dallas, Texas, USA > >

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Re: Is there a list of "current" time zones?
by Eric Ulevik July 10, 2007

July 10, 2007

On 7/10/07, Tim Klein <tkpublic(a)timklein.fastmail.fm> wrote: > I'm helping to write an application that needs a menu for the user to > choose what time zone they live in. With ~400 time zones in the > database, that'd be a pretty daunting pull-down menu. You will find this menu in quite a few places. Generally people don't have a problem identifying their geographical location - which is what this list shows. To simplify the menu, get the user to first choose a continent (eg. "Australia" or "Europe") then a region from a smaller list. You could also move the most common selections to the top of the list. Regards, Eric Ulevik

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French Polynesia time zones
by Jesper Norgaard Welen July 9, 2007

July 9, 2007

Perhaps the following link will interest Eric Muller and the rest of the mailing list members: http://www.timegenie.com/country.time/pf/ The FAQ mentioned of the Tahiti tourism web site in fact has the URL http://www.tahiti-tourisme.com/planner/tahitifaqs.asp (it seems to have changed name since timegenie site documented it). Eric asked for a recognition of the three time zones in the tz database for French Polynesia. The explanation in the timegenie web site is: "According to the official <http://www.tahiti-tourisme.com/> Tahiti Tourisme web site, Tahiti and her Islands have two times zones. This information can be found in the <http://www.tahiti-tourisme.com/planner/faqs.asp> FAQ section. However, Tahiti and her islands have in fact three time zones. The third time zone is not mentioned on the Tahiti Tourisme web site. Most likely, the third time zone is not mentioned since it is not visited by many tourists due to its distance from the main island of Tahiti. Since there is no official mention of the third time zone, timegenie.com contacted a Tahiti Tourisme office by phone. The result was that timegenie.com received official confirmation of the third time zone. Based on the information provided by Tahiti Tourisme, the majority of the islands, including the island of Tahiti itself, are -10 hours UTC/GMT. The Marquesas Islands are -9 hours 30 minutes UTC/GMT. The Gambier Islands are the third time zone and they are -9 hours UTC/GMT." I hope it's alright to quote timegenie for this information. I haven't found myself an official French Polynesia goverment web site confirming this information, but my french is limited to a 40-hour course so it is not to much use in this investigation. 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 shareware program World Time Explorer, I made: http://www.worldtimeexplorer.com/index.html

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French Polynesia
by Eric Muller July 3, 2007

July 3, 2007

If I read correctly the tz data for French Polynesia, there are three tz zones that are half an hour apart. I searched for an independent confirmation, but I can't find any evidence that FP has multiple local times. The best I have found so far is <http://www.outre-mer.gouv.fr/outremer/front?id=outremer/decouvrir_outre_mer…> which suggests that all of FP is in a single timezone. Any idea of the source of the current data? Thanks, Eric.

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