Multiple time zones in Mongolia

Paul Eggert eggert at
Sat Dec 11 23:48:32 UTC 1999

   Date: Sat, 11 Dec 1999 06:43:46 +0100
   From: Oscar van Vlijmen <o.van.vlijmen at>

   I think it is safe to assume that Mongolia has two time zones.

Thanks for your information and references; I'll incorporate them into
my next set of proposed changes.  I'll CC: this message to the tz
mailing list in case someone else can contribute info about Mongolia.
Shanks writes that the Mongolian UTC+9 time zone didn't exist until
1983; perhaps it vanished some time between then and now.

   No one mentions DST.

The IATA formerly agreed with Shanks that Mongolia observed DST, but
the most recent issue of the SSIM (dated 1999-09) no longer says this.
For lack of better information, I'll assume that Mongolia stopped
observing DST starting this year.

   I think you should not use Dariv as the central place in the UTC+7
   time zone.  Take the more obvious Hovd. There are two Hovd in
   Mongolia, so you should add the alternative name Jargalant.

Jargalant is problematic.  Rand McNally spells it Jirgalanta.  Shanks
spells it Dzargalant (with a hacek over the z), or as Chovd.  The CIA
spells it something like Duno-Us; I can't quite read the scanned image in

We generally prefer the most populous location to represent a region,
so we should use the most populous location in Hovd, Uvs, and
Bayan-Olgiy.  I suspect that the candidates are Jargalant (the capital
of Hovd), Ulaangom (the capital of Uvs), and Olgiy (the capital of
Bayan-Olgiy).  Do you happen to know which is the most populous?
Olgiy doesn't make it into Goode's, so I assume that it's smaller.  If
Ulaangom is larger than Jargalant, or if we can't figure out which is
the larger, then I'd prefer to use Ulaangom, as its spelling is less

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