Historically distinct IANA time zone
Asia/Ulaanbaatar
- Countries
- Mongolia
- GPS reference
- 47.92° N, 106.88° E
- Data source
- IANA asia
- Aliases
- Asia/Choibalsan, Asia/Ulan_Bator
- Rule groups
- Mongol
Mongoliamost of Mongolia
Geographic context
Where this clock belongs
The map marks the IANA reference location and associated country, not a time-zone boundary.
GPS reference: 47.92° N, 106.88° E. Associated countries: MN.
The Wikipedia link provides additional context; it is not evidence for a historical claim. Transition data comes from the IANA source file.
Notes from the time database
The story behind the clock
These source notes describe a period or rule. They do not, by themselves, establish a causal claim for a particular clock change.
IATA SSIM (1999-09) says Mongolia no longer observes DST.
Original IANA source file: asia.
A shared present
Same clock today, different past
These nearby zones follow the same current annual pattern, yet retain their own historical record.
Russia · 517 km from the reference location · Same annual clock since 2017
Brunei · 4840 km from the reference location · Same annual clock since 2017
Malaysia · 5001 km from the reference location · Same annual clock since 2017Civil-time record
Recorded changes over time
From 1905 to 2016 · 50 recorded transitions
Recurring daylight-saving changes are grouped separately when JavaScript is available.
Notable changes
One-off changes and transitions outside the recurring seasonal rhythm.
- +07:00 · +07Standard time applies
- +08:00 · +08Standard time applies
- +09:00 · +09Daylight saving time begins
- +08:00 · +08Standard time applies
- +09:00 · +09Daylight saving time begins
- +08:00 · +08Standard time applies
Browse every recorded transition
| Local time after transition | Offset after | Abbreviation | Rule |
|---|---|---|---|
| 1905-07-31 23:52 | +07:00 | +07 | Standard time |
| 1978-01-01 01:00 | +08:00 | +08 | Standard time |
| 1983-04-01 01:00 | +09:00 | +09 | Daylight saving time |
| 1983-09-30 23:00 | +08:00 | +08 | Standard time |
| 1984-04-01 01:00 | +09:00 | +09 | Daylight saving time |
| 1984-09-29 23:00 | +08:00 | +08 | Standard time |
| 1985-03-31 01:00 | +09:00 | +09 | Daylight saving time |
| 1985-09-28 23:00 | +08:00 | +08 | Standard time |
| 1986-03-30 01:00 | +09:00 | +09 | Daylight saving time |
| 1986-09-27 23:00 | +08:00 | +08 | Standard time |
| 1987-03-29 01:00 | +09:00 | +09 | Daylight saving time |
| 1987-09-26 23:00 | +08:00 | +08 | Standard time |
| 1988-03-27 01:00 | +09:00 | +09 | Daylight saving time |
| 1988-09-24 23:00 | +08:00 | +08 | Standard time |
| 1989-03-26 01:00 | +09:00 | +09 | Daylight saving time |
| 1989-09-23 23:00 | +08:00 | +08 | Standard time |
| 1990-03-25 01:00 | +09:00 | +09 | Daylight saving time |
| 1990-09-29 23:00 | +08:00 | +08 | Standard time |
| 1991-03-31 01:00 | +09:00 | +09 | Daylight saving time |
| 1991-09-28 23:00 | +08:00 | +08 | Standard time |
| 1992-03-29 01:00 | +09:00 | +09 | Daylight saving time |
| 1992-09-26 23:00 | +08:00 | +08 | Standard time |
| 1993-03-28 01:00 | +09:00 | +09 | Daylight saving time |
| 1993-09-25 23:00 | +08:00 | +08 | Standard time |
| 1994-03-27 01:00 | +09:00 | +09 | Daylight saving time |
| 1994-09-24 23:00 | +08:00 | +08 | Standard time |
| 1995-03-26 01:00 | +09:00 | +09 | Daylight saving time |
| 1995-09-23 23:00 | +08:00 | +08 | Standard time |
| 1996-03-31 01:00 | +09:00 | +09 | Daylight saving time |
| 1996-09-28 23:00 | +08:00 | +08 | Standard time |
| 1997-03-30 01:00 | +09:00 | +09 | Daylight saving time |
| 1997-09-27 23:00 | +08:00 | +08 | Standard time |
| 1998-03-29 01:00 | +09:00 | +09 | Daylight saving time |
| 1998-09-26 23:00 | +08:00 | +08 | Standard time |
| 2001-04-28 03:00 | +09:00 | +09 | Daylight saving time |
| 2001-09-29 01:00 | +08:00 | +08 | Standard time |
| 2002-03-30 03:00 | +09:00 | +09 | Daylight saving time |
| 2002-09-28 01:00 | +08:00 | +08 | Standard time |
| 2003-03-29 03:00 | +09:00 | +09 | Daylight saving time |
| 2003-09-27 01:00 | +08:00 | +08 | Standard time |
| 2004-03-27 03:00 | +09:00 | +09 | Daylight saving time |
| 2004-09-25 01:00 | +08:00 | +08 | Standard time |
| 2005-03-26 03:00 | +09:00 | +09 | Daylight saving time |
| 2005-09-24 01:00 | +08:00 | +08 | Standard time |
| 2006-03-25 03:00 | +09:00 | +09 | Daylight saving time |
| 2006-09-30 01:00 | +08:00 | +08 | Standard time |
| 2015-03-28 03:00 | +09:00 | +09 | Daylight saving time |
| 2015-09-25 23:00 | +08:00 | +08 | Standard time |
| 2016-03-26 03:00 | +09:00 | +09 | Daylight saving time |
| 2016-09-23 23:00 | +08:00 | +08 | Standard time |