Offset
The time difference between Western Indonesia Time and Mountain Time is 13 hours.
Western Indonesia Time (WIB) is ahead of Mountain Time (MDT).
WIB: UTC+7
MDT: UTC-6
Mountain Time is currently observing daylight saving time; Western Indonesia Time is not.
When to schedule
Standard business hours (9 AM–5 PM, Mon–Fri) in Western Indonesia Time and Mountain Time don't overlap on the same weekday. Mountain Time is 13 hours behind Western Indonesia Time.
Realistic options: hand off asynchronously, or stretch one side by an hour to catch the other team at the start or end of their day.
This window may shift by an hour during daylight saving time.
Public holidays in 2026
National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.
Indonesia
- New Year's DayThu, Jan 1
- Good FridayFri, Apr 3
- Easter SundaySun, Apr 5
- Labour DayFri, May 1
- Ascension DayThu, May 14
- Pancasila DayMon, Jun 1
- Independence DayMon, Aug 17
- Christmas DayFri, Dec 25
United States
- New Year's DayThu, Jan 1
- Martin Luther King, Jr. DayMon, Jan 19
- Presidents DayMon, Feb 16
- Memorial DayMon, May 25
- Juneteenth National Independence DayFri, Jun 19
- Independence DayFri, Jul 3
- Labour DayMon, Sep 7
- Columbus DayMon, Oct 12
- Veterans DayWed, Nov 11
- Thanksgiving DayThu, Nov 26
- Christmas DayFri, Dec 25
About these zones
Western Indonesia Time is also known as WIB. To call Indonesia, dial +62.
Mountain Time is also known as MST, or MDT. To call United States, dial +1.
Mountain Time is approximately 9,400 miles northeast of Western Indonesia Time.
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| WIB | MST | Day |
|---|---|---|
| 12:00 am | 11:00 am | -1 day |
| 1:00 am | 12:00 pm | -1 day |
| 2:00 am | 1:00 pm | -1 day |
| 3:00 am | 2:00 pm | -1 day |
| 4:00 am | 3:00 pm | -1 day |
| 5:00 am | 4:00 pm | -1 day |
| 6:00 am | 5:00 pm | -1 day |
| 7:00 am | 6:00 pm | -1 day |
| 8:00 am | 7:00 pm | -1 day |
| 9:00 am | 8:00 pm | -1 day |
| 10:00 am | 9:00 pm | -1 day |
| 11:00 am | 10:00 pm | -1 day |
| 12:00 pm | 11:00 pm | -1 day |
| 1:00 pm | 12:00 am | Same day |
| 2:00 pm | 1:00 am | Same day |
| 3:00 pm | 2:00 am | Same day |
| 4:00 pm | 3:00 am | Same day |
| 5:00 pm | 4:00 am | Same day |
| 6:00 pm | 5:00 am | Same day |
| 7:00 pm | 6:00 am | Same day |
| 8:00 pm | 7:00 am | Same day |
| 9:00 pm | 8:00 am | Same day |
| 10:00 pm | 9:00 am | Same day |
| 11:00 pm | 10:00 am | Same day |
Daylight saving time
Mountain Time observes daylight saving time; Western Indonesia Time does not. The offset between the two zones changes when Mountain Time transitions: on Sunday, November 1, 2026, clocks fall back from MDT to MST.
See the daylight saving time page for transition dates across every time zone.
Daylight today
- Sunrise
- 5:59 AM
- Sunset
- 5:45 PM
- Day length
- 11h 47m
- Sunrise
- 5:34 AM
- Sunset
- 8:25 PM
- Day length
- 14h 51m
Daylight overlap: 3h 26m — 5:59 AM–9:25 AM in Western Indonesia Time (4:59 PM–8:25 PM in Mountain Time). Both locations are in daylight during this window.
Cities in these zones
Cities in Western Indonesia Time
Cities in Mountain Time
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Western Indonesia Time
- CGK
- HLP
- SUB
- BDO
- KNO
- PLM
- SRG
Airports in Mountain Time
- BJC
- DEN
- OGD
- SLC
Related conversions
Common conversions
- What is 9:00 am WIB in MST?
- 9:00 am WIB is 8:00 pm MST, the previous day.
- What is 12:00 pm WIB in MST?
- 12:00 pm WIB is 11:00 pm MST, the previous day.
- What is 12:30 pm WIB in MST?
- 12:30 pm WIB is 11:30 pm MST, the previous day.
- What is 2:00 pm WIB in MST?
- 2:00 pm WIB is 1:00 am MST.
- What is 5:00 pm WIB in MST?
- 5:00 pm WIB is 4:00 am MST.
- What is 11:30 pm WIB in MST?
- 11:30 pm WIB is 10:30 am MST.