Offset
The time difference between Arabia Standard Time and Mountain Time is 9 hours.
Arabia Standard Time (AST) is ahead of Mountain Time (MDT).
AST: UTC+3
MDT: UTC-6
Mountain Time is currently observing daylight saving time; Arabia Standard Time is not.
When to schedule
Standard business hours (9 AM–5 PM, Mon–Fri) in Arabia Standard Time and Mountain Time don't overlap on the same weekday. Mountain Time is 9 hours behind Arabia Standard Time.
With some flexibility, there’s a workable window outside standard hours:
- 4 PM–8 PM in Arabia Standard Time (7 AM–11 AM in Mountain Time) — suggest 6:00 PM Arabia Standard Time (9:00 AM Mountain Time).
This means an early start or late finish for one side, but it’s a reasonable slot for a one-off meeting.
This window may shift by an hour during daylight saving time.
Note: the working week in Saudi Arabia runs Sunday–Thursday; Friday–Saturday is the weekend, so overlap on those days is limited.
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.
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
Arabia Standard Time is also known as AST. To call Saudi Arabia, dial +966.
Mountain Time is also known as MST, or MDT. To call United States, dial +1.
Mountain Time is approximately 7,600 miles northwest of Arabia Standard Time.
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| AST | MST | Day |
|---|---|---|
| 12:00 am | 3:00 pm | -1 day |
| 1:00 am | 4:00 pm | -1 day |
| 2:00 am | 5:00 pm | -1 day |
| 3:00 am | 6:00 pm | -1 day |
| 4:00 am | 7:00 pm | -1 day |
| 5:00 am | 8:00 pm | -1 day |
| 6:00 am | 9:00 pm | -1 day |
| 7:00 am | 10:00 pm | -1 day |
| 8:00 am | 11:00 pm | -1 day |
| 9:00 am | 12:00 am | Same day |
| 10:00 am | 1:00 am | Same day |
| 11:00 am | 2:00 am | Same day |
| 12:00 pm | 3:00 am | Same day |
| 1:00 pm | 4:00 am | Same day |
| 2:00 pm | 5:00 am | Same day |
| 3:00 pm | 6:00 am | Same day |
| 4:00 pm | 7:00 am | Same day |
| 5:00 pm | 8:00 am | Same day |
| 6:00 pm | 9:00 am | Same day |
| 7:00 pm | 10:00 am | Same day |
| 8:00 pm | 11:00 am | Same day |
| 9:00 pm | 12:00 pm | Same day |
| 10:00 pm | 1:00 pm | Same day |
| 11:00 pm | 2:00 pm | Same day |
Daylight saving time
Mountain Time observes daylight saving time; Arabia Standard 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
- 5:05 AM
- Sunset
- 6:41 PM
- Day length
- 13h 36m
- Sunrise
- 5:34 AM
- Sunset
- 8:25 PM
- Day length
- 14h 51m
Daylight overlap: 20m — 5:05 AM–5:25 AM in Arabia Standard Time (8:05 PM–8:25 PM in Mountain Time). Both locations are in daylight during this window.
Cities in these zones
Cities in Mountain Time
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Arabia Standard Time
- JED
- RUH
- MED
- DMM
Airports in Mountain Time
- BJC
- DEN
- OGD
- SLC
Related conversions
Common conversions
- What is 9:00 am AST in MST?
- 9:00 am AST is 12:00 am MST.
- What is 12:00 pm AST in MST?
- 12:00 pm AST is 3:00 am MST.
- What is 12:30 pm AST in MST?
- 12:30 pm AST is 3:30 am MST.
- What is 2:00 pm AST in MST?
- 2:00 pm AST is 5:00 am MST.
- What is 5:00 pm AST in MST?
- 5:00 pm AST is 8:00 am MST.
- What is 11:30 pm AST in MST?
- 11:30 pm AST is 2:30 pm MST.