AST to MST Converter
Time Difference
Atlantic Daylight Time is 3 hours ahead of Mountain Daylight Time
7:30 pm19:30 in ADT is 4:30 pm16:30 in MDT
AST to MST call time
Best time for a conference call or a meeting is between 11am-6pm in AST which corresponds to 8am-3pm in MST
7:30 pm19:30 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
4:30 pm16:30 Mountain Daylight Time (MDT). Offset UTC -6:00 hours
7:30 pm19:30 ADT / 4:30 pm16:30 MDT
| ADT | MDT |
|---|---|
| 12am (midnight) | 9pm |
| 1am | 10pm |
| 2am | 11pm |
| 3am | 12am (midnight) |
| 4am | 1am |
| 5am | 2am |
| 6am | 3am |
| 7am | 4am |
| 8am | 5am |
| 9am | 6am |
| 10am | 7am |
| 11am | 8am |
| 12pm (noon) | 9am |
| 1pm | 10am |
| 2pm | 11am |
| 3pm | 12pm (noon) |
| 4pm | 1pm |
| 5pm | 2pm |
| 6pm | 3pm |
| 7pm | 4pm |
| 8pm | 5pm |
| 9pm | 6pm |
| 10pm | 7pm |
| 11pm | 8pm |
| 0:00 | 21:00 |
| 1:00 | 22:00 |
| 2:00 | 23:00 |
| 3:00 | 0:00 |
| 4:00 | 1:00 |
| 5:00 | 2:00 |
| 6:00 | 3:00 |
| 7:00 | 4:00 |
| 8:00 | 5:00 |
| 9:00 | 6:00 |
| 10:00 | 7:00 |
| 11:00 | 8:00 |
| 12:00 | 9:00 |
| 13:00 | 10:00 |
| 14:00 | 11:00 |
| 15:00 | 12:00 |
| 16:00 | 13:00 |
| 17:00 | 14:00 |
| 18:00 | 15:00 |
| 19:00 | 16:00 |
| 20:00 | 17:00 |
| 21:00 | 18:00 |
| 22:00 | 19:00 |
| 23:00 | 20:00 |
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries: It is used in following countries: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)
Principal Cities: The largest city in the AST timezone is Santo Domingo from Dominican Republic with population about 2.202 million people. Other major cities in the area are Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico
Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Atlantic Daylight Time (ADT).
End: Atlantic Standard Time (AST) has ended on Sunday, March 9, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, March 9, 2025, 3:00 am local daylight time instead. Standard time ends annually the on second Sunday of March.
Start: Atlantic Standard Time (AST) starts on Sunday, November 2, 2025 at 2:00 am local time and clocks are set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually the on first Sunday of November.
AST representations, usage and related time zones
- -04 - basic short
- -0400 - basic
- -04:00 - extended
- -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates four hour and zero minutes time differences to the west of the zero meridian.
- Quebec - Military abbreviation for AST
- Q - short form of 'Quebec'
- America/Anguilla
- America/Antigua
- America/Aruba
- America/Barbados
- America/Blanc-Sablon
- America/Curacao
- America/Dominica
- America/Glace_Bay
- America/Goose_Bay
- America/Grenada
- America/Guadeloupe
- America/Halifax
- America/Kralendijk
- America/Lower_Princes
- America/Marigot
- America/Martinique
- America/Moncton
- America/Montserrat
- America/Port_of_Spain
- America/Puerto_Rico
- America/Santo_Domingo
- America/St_Barthelemy
- America/St_Kitts
- America/St_Lucia
- America/St_Thomas
- America/St_Vincent
- America/Thule
- America/Tortola
- America/Virgin
- Atlantic/Bermuda
- Canada/Atlantic
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- Argentina Standard Time - UTC -3
- Armenia Standard Time - UTC +4
- Azores Summer Time - UTC +0
- Apia Standard Time - UTC +13
- AST - Atlantic Standard Time
- EDT - Eastern Daylight Time
- AMT - Amazon Time
- BOT - Bolivia Time
- CDT - Cuba Daylight Time
- CLT - Chile Standard Time
- FKT - Falkland Island Time
- GYT - Guyana Time
- HLV - Hora Legal de Venezuela
- PYT - Paraguay Time
- Q - Quebec Time Zone
- VET - Venezuelan Standard Time
Mountain Standard Time
Offset: MST is 7 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries: It is used in following countries: Canada, Mexico, United States
Principal Cities: The largest city in the MST timezone is Phoenix from USA with population about 1.446 million people. Other major cities in the area are Calgary, Edmonton, El Paso, Denver
French: HNR - Heure Normale des Rocheuses
Spanish: MT - Zona Pacífico
Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Mountain Daylight Time (MDT).
End: Mountain Standard Time (MST) has ended on Sunday, March 9, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, March 9, 2025, 3:00 am local daylight time instead. Standard time ends annually the on second Sunday of March.
Start: Mountain Standard Time (MST) starts on Sunday, November 2, 2025 at 2:00 am local time and clocks are set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually the on first Sunday of November.
MST representations, usage and related time zones
- -07 - basic short
- -0700 - basic
- -07:00 - extended
- -0700 - sign character (-) followed by a four digit time providing hours (07) and minutes (00) of the offset. Indicates seven hour and zero minutes time differences to the west of the zero meridian.
- Tango - Military abbreviation for MST
- T - short form of 'Tango'
- America/Boise
- America/Cambridge_Bay
- America/Ciudad_Juarez
- America/Creston
- America/Dawson
- America/Dawson_Creek
- America/Denver
- America/Edmonton
- America/Fort_Nelson
- America/Hermosillo
- America/Inuvik
- America/Mazatlan
- America/Phoenix
- America/Shiprock
- America/Whitehorse
- America/Yellowknife
- Canada/Mountain
- Canada/Yukon
- MST
- MST7MDT
- Mexico/BajaSur
- Navajo
- US/Arizona
- US/Mountain
- Mountain Standard Time - UTC -7
- Moscow Standard Time - UTC +3
- Mauritius Standard Time - UTC +4
- MST - Mountain Standard Time
- PDT - Pacific Daylight Time
- YST - Yukon Standard Time
- T - Tango Time Zone