Hello, Sources about time zones in Mongolia seem to list one of two conflicting configurations. The first configuration, mentioned in a comment to the TZ database in 1999, citing a Mongolian government website, lists the provinces of Bayan-Ölgii, Khovd and Uvs in UTC+7, and the rest of the country in UTC+8. The second configuration, mentioned in a comment to the database in 2001, lists Bayan-Ölgii, Khovd, Uvs, Govi-Altai and Zavkhan in UTC+7, Dornod and Sükhbaatar in UTC+9, and the rest of the country in UTC+8. The first configuration is still mentioned by several Mongolian travel agencies: https://www.adventurerider.mn/en/page/about_mongolia http://www.naturetours.mn/nt/mongolia.php https://www.newjuulchin.mn/web/content/7506?unique=fa24a0f6e96e022a3578ee519... It also matches these flight schedules in 2013: http://web.archive.org/web/20130722023600/https://www.hunnuair.com/en/timeta... The flight times imply that the airports of Uliastai (Zavkhan), Choibalsan (Dornod) and Altai (Govi-Altai) are in the same time zone as Ulaanbaatar, and Khovd is one hour behind. It also matches a Mongolian news article about the election in 2017: https://mongolia.gogo.mn/r/806d6 The second configuration was mentioned by an official of the Mongolian standards agency in an interview in 2014: https://ikon.mn/n/9v6 And it's still listed by the Mongolian aviation agency: https://ais.mn/files/aip/eAIP/2023-12-25/html/eSUP/ZM-eSUP-23-04-en-MN.html The TZ database used the first configuration until 2001, when it switched to the second configuration, under the assumption that its sources were more reliable. In 2008, based on sources indicating that Choibalsan actually used UTC+8, the database changed Dornod and Sükhbaatar to UTC+8, but only from 2008 on, and maintained Govi-Altai and Zavkhan in UTC+7. This resulted in a mix of the two configurations that is not supported as a whole by any source. Based on all the above sources, I believe that the first configuration is what is actually observed in Mongolia and has been so all along, at least since 1999. The second configuration closely matches the ideal time zone boundaries at 97.5°E and 112.5°E but it doesn't seem to be used in practice. So I suggest the following: 1. In zone.tab, remove Govi-Altai and Zavkhan from Asia/Ulaanbaatar, assuming that they have always used the same time as Ulaanbaatar, or create a new zone Asia/Uliastai showing Govi-Altai and Zavkhan in UTC+8 since at least 1999. 2. Remove the zone Asia/Choibalsan or make it an alias of Asia/Ulaanbaatar, assuming that it has always used the same time as Ulaanbaatar, or list its change from UTC+9 to UTC+8 since at least 1999 instead of 2008. Regards,Dave | | Virus-free.www.avg.com |
Thanks for that analysis of our conflicting data about Mongolia. On balance I'm inclined to agree with you that part of our 2008 change that was at the time marked "this is almost surely wrong" is best reverted, and installed the attached patch which incorporates your analysis and takes your first proposed solution, which is simpler. I had one quibble, though: On 6/24/24 00:03, Heitor David Pinto via tz wrote:
It also matches a Mongolian news article about the election in 2017: https://mongolia.gogo.mn/r/806d6
That news article doesn't cast light on the matter, because when it was written the polls would have been closed in the central and eastern regions of Mongolia regardless of whether Mongolia had two time zones or three. So I omitted that citation in the commentary of the attached proposed patch, which I installed in the development repository.
Hi, Paul, Thank you for accepting my suggestions. I had mentioned the news article about the election to confirm that the provinces using UTC+7 were only Bayan-Ölgii, Khovd and Uvs, but not Govi-Altai and Zavkhan. But you're right, this article doesn't clarify the time zone of eastern Mongolia. Regards,David On Wednesday, July 3, 2024 at 06:31:48 AM EDT, Paul Eggert <eggert@cs.ucla.edu> wrote: Thanks for that analysis of our conflicting data about Mongolia. On balance I'm inclined to agree with you that part of our 2008 change that was at the time marked "this is almost surely wrong" is best reverted, and installed the attached patch which incorporates your analysis and takes your first proposed solution, which is simpler. I had one quibble, though: On 6/24/24 00:03, Heitor David Pinto via tz wrote:
It also matches a Mongolian news article about the election in 2017: https://mongolia.gogo.mn/r/806d6
That news article doesn't cast light on the matter, because when it was written the polls would have been closed in the central and eastern regions of Mongolia regardless of whether Mongolia had two time zones or three. So I omitted that citation in the commentary of the attached proposed patch, which I installed in the development repository.
participants (2)
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Heitor David Pinto -
Paul Eggert