Canada Atlantic Time to US Mountain Time
Convert times between Canada Atlantic Time (AST, UTC-4:00) and US Mountain Time (MST, UTC-7:00). US Mountain Time is 3 hours behind Canada Atlantic Time in standard time.
UTC-4:00 / -3:00→UTC-7:00 / -6:00
Live timezone converterUTC Offset Reference
| Timezone | Abbreviation | Standard offset | DST offset | Country |
|---|---|---|---|---|
| Canada Atlantic Time | AST / ADT | UTC-4:00 | UTC-3:00 | Canada |
| US Mountain Time | MST / MDT | UTC-7:00 | UTC-6:00 | United States |
* DST offset applies during summer months. Exact transition dates vary by year.
Standard Time Conversion (AST → MST)
| Canada Atlantic Time | US Mountain Time |
|---|---|
| 12:00 AM AST | 9:00 PM (prev day) MST |
| 6:00 AM AST | 3:00 AM MST |
| 9:00 AM AST | 6:00 AM MST |
| 12:00 PM AST | 9:00 AM MST |
| 3:00 PM AST | 12:00 PM MST |
| 6:00 PM AST | 3:00 PM MST |
| 9:00 PM AST | 6:00 PM MST |
Daylight Saving Time (DST) Notes
- Canada Atlantic Time observes DST. Clocks advance 1 hour to ADT (UTC-3:00) roughly from month 3 to 11.
- US Mountain Time observes DST. Clocks advance 1 hour to MDT (UTC-6:00) roughly from month 3 to 11.
Frequently Asked Questions
How do I convert AST to MST?
Add (-3) hours to the AST time to get MST. For example, 9:00 AM AST = 6:00 AM MST.
What is the current UTC offset for Canada Atlantic Time?
Canada Atlantic Time is UTC-4:00 during standard time (AST) and UTC-3:00 during summer daylight saving time (ADT).
Is US Mountain Time ahead or behind Canada Atlantic Time?
US Mountain Time is 3 hours behind Canada Atlantic Time in standard time.
When is a good time to schedule a meeting between AST and MST?
A good overlap window is around 12:00 PM AST / 9:00 AM MST, which falls within business hours for both timezones.
Related Timezone Conversions
Canada Atlantic Time → US Eastern TimeAST / ESTCanada Atlantic Time → US Central TimeAST / CSTCanada Atlantic Time → US Pacific TimeAST / PSTCanada Atlantic Time → US Alaska TimeAST / AKSTCanada Atlantic Time → Hawaii TimeAST / HSTCanada Atlantic Time → Greenwich Mean TimeAST / GMTCanada Atlantic Time → India Standard TimeAST / ISTCanada Atlantic Time → China Standard TimeAST / CST
Need the exact current time?
Use the live ToolsHub timezone converter to see current times, DST status, and schedule across time zones.