Time zone · Asia
UST
Ulaanbaatar Standard Time
Ulaanbaatar Standard Time (UST) keeps Mongolia running on a steady UTC+08:00 rhythm—no daylight saving changes, just consistent scheduling across the steppes. It covers most of Mongolia, including Ulaanbaatar; the western provinces of Bayan-Ölgii, Khovd and Uvs use UTC+07:00.
Thursday, October 15, 2026
Current offset
UTC+08:00
Standard · +08
Daylight saving
Not observed
Year-round standard time
IANA zones
1
None observe daylight saving
DST offset
—
No summer variant
About UST
A fixed, year-round offset.
Ulaanbaatar Standard Time (UST) keeps Mongolia running on a steady UTC+08:00 rhythm—no daylight saving changes, just consistent scheduling across the steppes. It covers most of Mongolia, including Ulaanbaatar; the western provinces of Bayan-Ölgii, Khovd and Uvs use UTC+07:00.
IANA zones · the technical identifiers
The zone that resolve to UST.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Cities across UST
Local time, city by city.
1 city
Where UST is used
One country.
Same offset · UTC+08:00
Other zones at UTC+08:00 right now.
These named zones share UST's offset today. When daylight saving rules differ, they drift apart for part of the year.
Convert
UST to the world's clocks.
Frequently asked questions
Common questions about UST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- What countries use Ulaanbaatar Standard Time?
- Only Mongolia uses Ulaanbaatar Standard Time. It covers most of the country, including Ulaanbaatar; the far west uses UTC+07:00.
- Does Mongolia observe daylight saving time?
- No, Mongolia does not observe daylight saving—UST stays fixed at UTC+08:00 year-round.
- When was Mongolia’s current time zone structure established?
- Ulaanbaatar has used UTC+08:00 as its standard time since 1978. Mongolia's last daylight saving period ended on 24 September 2016, and it has not changed its clocks since.
- How does having a single time zone affect life and business in Mongolia?
- Most of Mongolia, including Ulaanbaatar, follows the same clock, which keeps national schedules simple. The western provinces of Bayan-Ölgii, Khovd and Uvs are one hour behind, on UTC+07:00.
- What’s the relationship between UST and neighboring time zones?
- UST aligns with several East Asia regions like China Standard Time (CST), making cross-border work smoother without worrying about offset shifts.
- Why doesn’t Mongolia adopt daylight saving time?
- Mongolia has tried daylight saving time several times, most recently in 2015 and 2016. The government dropped it again in early 2017, and clocks have stayed on UTC+08:00 since.
Source: IANA tzdb2026d · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
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