AST to GMT Converter
Quick answers
AST is 4 hours behind GMT. AST uses GMT -4, and GMT uses GMT +0 for this comparison.
For example, 8:00 am AST is 12:00 pm GMT. Use the converter above to adjust the date or time and create a shareable meeting link.
Best meeting overlap: 9am-1pm AST, which is 1pm-5pm GMT.
Compare AST time with GMT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Atlantic Standard Time is 4 hours behind Greenwich Mean Time
8:00 am08:00 in AST is 12:00 pm12:00 in GMT
AST to GMT call time
Best time for a conference call or a meeting is between 9am-1pm in AST which corresponds to 1pm-5pm in GMT
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
8:00 am08:00 AST / 12:00 pm12:00 GMT
| AST | GMT |
|---|---|
| 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 | 12am (midnight) |
| 9pm | 1am |
| 10pm | 2am |
| 11pm | 3am |
| 00:00 | 04:00 |
| 01:00 | 05:00 |
| 02:00 | 06:00 |
| 03:00 | 07:00 |
| 04:00 | 08:00 |
| 05:00 | 09:00 |
| 06:00 | 10:00 |
| 07:00 | 11:00 |
| 08:00 | 12:00 |
| 09:00 | 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 | 00:00 |
| 21:00 | 01:00 |
| 22:00 | 02:00 |
| 23:00 | 03:00 |
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries using this time zone: 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 time zone is Santo Domingo in Dominican Republic, with about 2.202 million people. Other major cities in this time zone include 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. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).
Start: Atlantic Standard Time (AST) started on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the first Sunday of November.
End: Atlantic Standard Time (AST) ends on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.
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 an offset of four hours 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
- 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
Greenwich Mean Time
Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe
Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo
Principal Cities: The largest city in the GMT time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Abidjan, Dakar, Grand Dakar, Accra.
Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.
GMT representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for GMT
- Z - short form of 'Zulu'
- Africa/Abidjan
- Africa/Accra
- Africa/Bamako
- Africa/Banjul
- Africa/Bissau
- Africa/Conakry
- Africa/Dakar
- Africa/Freetown
- Africa/Lome
- Africa/Monrovia
- Africa/Nouakchott
- Africa/Ouagadougou
- Africa/Sao_Tome
- Africa/Timbuktu
- America/Danmarkshavn
- Atlantic/Reykjavik
- Atlantic/St_Helena
- Eire
- Etc/GMT
- Etc/GMT+0
- Etc/GMT-0
- Etc/GMT0
- Etc/Greenwich
- Europe/Belfast
- Europe/Dublin
- Europe/Guernsey
- Europe/Isle_of_Man
- Europe/Jersey
- Europe/London
- GB
- GB-Eire
- GMT
- GMT+0
- GMT-0
- GMT0
- Greenwich
- Iceland
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Universal Time Coordinated
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone