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GST to MST converter
Gulf Standard Time
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Mountain Time
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Mountain Time is 10 hours behind Gulf Standard Time for most of the year, and 11 hours behind for part of it, because the two change their clocks on different dates (or only one of them changes at all).
When does the difference change?
In 2026:
- January 1 to March 7: Mountain Time is 11 hours behind Gulf Standard Time
- March 8 to October 31: Mountain Time is 10 hours behind Gulf Standard Time
- November 1 to December 31: Mountain Time is 11 hours behind Gulf Standard Time
Questions
What time is 9 AM GST in MST?
For most of the year, 9 AM Gulf Standard Time is 11 PM the day before Mountain Time. For part of the year it is 10 PM the day before, because of daylight saving time.
How many hours ahead or behind is MST from GST?
Mountain Time is 10 hours behind Gulf Standard Time for most of the year, and 11 hours behind for part of it, because the two change their clocks on different dates (or only one of them changes at all).
Does the GST to MST difference change?
Yes. It changes 2 times in 2026 because of daylight saving time.
About these time zones
GST to MST, hour by hour
| Gulf Standard Time | Mountain Time |
|---|---|
| 12 AM | 2 PM (previous day) |
| 1 AM | 3 PM (previous day) |
| 2 AM | 4 PM (previous day) |
| 3 AM | 5 PM (previous day) |
| 4 AM | 6 PM (previous day) |
| 5 AM | 7 PM (previous day) |
| 6 AM | 8 PM (previous day) |
| 7 AM | 9 PM (previous day) |
| 8 AM | 10 PM (previous day) |
| 9 AM | 11 PM (previous day) |
| 10 AM | 12 AM |
| 11 AM | 1 AM |
| 12 PM | 2 AM |
| 1 PM | 3 AM |
| 2 PM | 4 AM |
| 3 PM | 5 AM |
| 4 PM | 6 AM |
| 5 PM | 7 AM |
| 6 PM | 8 AM |
| 7 PM | 9 AM |
| 8 PM | 10 AM |
| 9 PM | 11 AM |
| 10 PM | 12 PM |
| 11 PM | 1 PM |
Based on the clocks on Monday, October 12, 2026. Use the converter above for another date.