AST to MST Converter
MST is 3 hours behind AST
AST to MST Conversion Table
Green rows indicate standard business hours (9 AM – 5 PM) in MST
| AST | MST |
|---|---|
| 12:00 AM | 9:00 PM -1d |
| 1:00 AM | 10:00 PM -1d |
| 2:00 AM | 11:00 PM -1d |
| 3:00 AM | 12:00 AM |
| 4:00 AM | 1:00 AM |
| 5:00 AM | 2:00 AM |
| 6:00 AM | 3:00 AM |
| 7:00 AM | 4:00 AM |
| 8:00 AM | 5:00 AM |
| 9:00 AM | 6:00 AM |
| 10:00 AM | 7:00 AM |
| 11:00 AM | 8:00 AM |
| 12:00 PM | 9:00 AM |
| 1:00 PM | 10:00 AM |
| 2:00 PM | 11:00 AM |
| 3:00 PM | 12:00 PM |
| 4:00 PM | 1:00 PM |
| 5:00 PM | 2:00 PM |
| 6:00 PM | 3:00 PM |
| 7:00 PM | 4:00 PM |
| 8:00 PM | 5:00 PM |
| 9:00 PM | 6:00 PM |
| 10:00 PM | 7:00 PM |
| 11:00 PM | 8:00 PM |
Converting Atlantic Standard Time to Mountain Standard Time
Atlantic Standard Time (AST) and Mountain Standard Time (MST) are separated by a 3 hours time difference. MST is 3 hours behind AST. AST is UTC-4, used in Canada, Puerto Rico, US Virgin Islands, while MST is UTC-7, used in United States, Canada.
When converting from AST to MST, the key reference points to remember are: 9:00 AM AST equals 6:00 AM MST, 12:00 PM noon AST equals 9:00 AM MST, and 5:00 PM AST equals 2:00 PM MST. The conversion table above shows every hour of the day mapped between these two time zones.
Scheduling Across AST and MST
For professionals scheduling meetings between AST and MST, finding overlapping business hours is essential. Standard business hours are typically 9:00 AM to 5:00 PM in each time zone. Given the 3 hours difference, the window of overlap may be limited. Use the highlighted working hours in the conversion table above to quickly identify suitable meeting times.
Daylight Saving Time Considerations
AST observes Daylight Saving Time, switching to ADT (UTC-3) during summer months. MST observes DST, switching to MDT (UTC-6). During DST transitions, the time difference between these zones may temporarily change by 1 hour. Always verify the current offset during spring and fall transition periods.