AST to ADT Converter
Atlantic Time is on daylight saving time: ADT (UTC−3) until Sun, Nov 1.
Quick answers
Selected conversion
9:00 am ADT (UTC-3), Oct 3, 2026 = 9:00 am ADT (UTC-3), Oct 3, 202609:00 ADT (UTC-3), Oct 3, 2026 = 09:00 ADT (UTC-3), Oct 3, 2026
ADT and ADT have the same local time.
AST and ADT examples
These examples always use AST (UTC-4) and ADT (UTC-3). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
AST is 1 hour behind ADT.
How the time difference changes
The AST and ADT converter rows show the same time year-round.
Working hours of 9:00 am to 5:00 pm on the AST converter row correspond to 9:00 am to 5:00 pm on the ADT converter row.Working hours of 09:00 to 17:00 on the AST converter row correspond to 09:00 to 17:00 on the ADT converter row.
Compare AST time with ADT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Atlantic Daylight Time is 0 hours ahead of Atlantic Daylight Time
9:00 am09:00 in ADT is 9:00 am09:00 in ADT
ADT to ADT call time
Best time for a conference call or a meeting is between 9am-5pm09:00-17:00 in ADT which corresponds to 9am-5pm09:00-17:00 in ADT
9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
9:00 am09:00 ADT / 9:00 am09:00 ADT
| ADT | ADT |
|---|---|
| 12am (midnight) | 12am (midnight) |
| 1am | 1am |
| 2am | 2am |
| 3am | 3am |
| 4am | 4am |
| 5am | 5am |
| 6am | 6am |
| 7am | 7am |
| 8am | 8am |
| 9am | 9am |
| 10am | 10am |
| 11am | 11am |
| 12pm (noon) | 12pm (noon) |
| 1pm | 1pm |
| 2pm | 2pm |
| 3pm | 3pm |
| 4pm | 4pm |
| 5pm | 5pm |
| 6pm | 6pm |
| 7pm | 7pm |
| 8pm | 8pm |
| 9pm | 9pm |
| 10pm | 10pm |
| 11pm | 11pm |
| 00:00 | 00:00 |
| 01:00 | 01:00 |
| 02:00 | 02:00 |
| 03:00 | 03:00 |
| 04:00 | 04:00 |
| 05:00 | 05:00 |
| 06:00 | 06:00 |
| 07:00 | 07:00 |
| 08:00 | 08:00 |
| 09:00 | 09:00 |
| 10:00 | 10:00 |
| 11:00 | 11:00 |
| 12:00 | 12:00 |
| 13:00 | 13:00 |
| 14:00 | 14:00 |
| 15:00 | 15:00 |
| 16:00 | 16:00 |
| 17:00 | 17:00 |
| 18:00 | 18:00 |
| 19:00 | 19:00 |
| 20:00 | 20:00 |
| 21:00 | 21:00 |
| 22:00 | 22:00 |
| 23:00 | 23:00 |
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, Halifax, San Juan.
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).
End: Atlantic Standard Time (AST) ended on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00 local daylight time instead. Standard time ends annually on the second Sunday of March.
Start: Atlantic Standard Time (AST) starts on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00. Standard time starts annually on the 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 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
Atlantic Daylight Time
Offset: ADT is 3 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries using this time zone: Bermuda, Canada, Greenland
Principal Cities: The largest city in the ADT time zone is Halifax in Canada, with about 471,559 people. Other major cities in this time zone include Sydney, Dartmouth, Moncton, Saint John.
French: HAA - Heure Avancée de l'Atlantique
Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Atlantic Standard Time (AST).
Start: Atlantic Daylight Time (ADT) started on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.
End: Atlantic Daylight Time (ADT) ends on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the first Sunday of November.
ADT representations, usage and related time zones
- -03 - basic short
- -0300 - basic
- -03:00 - extended
- -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates an offset of three hours to the west of the zero meridian.
- Papa - Military abbreviation for ADT
- P - short form of 'Papa'
- America/Glace_Bay
- America/Goose_Bay
- America/Halifax
- America/Moncton
- America/Thule
- Atlantic/Bermuda
- Canada/Atlantic
- ADT - Atlantic Daylight Time
- PMT - Pierre & Miquelon Standard Time
- PMST - Pierre & Miquelon Standard Time
- AMST - Amazon Summer Time
- ART - Argentina Time
- BRT - Brasília time
- CLST - Chile Summer Time
- FKST - Falkland Islands Summer Time
- GFT - French Guiana Time
- P - Papa Time Zone
- PYST - Paraguay Summer Time
- SRT - Suriname Time
- UYT - Uruguay Time