AST – Atlantic Standard Time / Atlantic Time (Standard Time)
Also known as: AT – Atlantic Time
North America: Only some locations are currently on AST because most places in this time zone are currently on summer time / daylight saving time and are observing ADT.
Atlantic: AST is currently not observed because locations are on summer time / daylight saving time and are observing ADT.
Observes AST part of the year.
Areas with same time currently (UTC -4).
Observes AST – Atlantic Standard Time part of the year, but not currently.
Currently has same time zone offset as AST (UTC -4) but different time zone name.
Atlantic Standard Time (AST) is 4 hours behind Coordinated Universal Time (UTC). This time zone is in use during standard time in: North America, Atlantic, Caribbean.
This time zone is often called Atlantic Time Zone.
Summer Time & DST
Some places observe daylight saving time/summer time during the summer, and therefore use ADT (Atlantic Daylight Time) in the summer.
Email Time Zone Indicator: -0400
An email sent from someone in the Atlantic Standard Time (AST) time zone will have the time zone listed as "-0400" in the headers of the email. (However, "-0400" does not have to be in Atlantic Standard Time, as other time zones could have the same UTC offset).
Where and When is AST Observed?
North America
Canadian provinces using AST in the winter and ADT in the summer:
- Most of Labrador (mainland part of the province of Newfoundland and Labrador)
- New Brunswick
- Nova Scotia
- Prince Edward Island
Canadian provinces using AST all year:
- Quebec - East of 63 West only.
Areas of Greenland using AST in the winter and ADT in the summer:
- Thule area
Atlantic
Atlantic islands/territories using AST in the winter and ADT in the summer:
- Bermuda
Caribbean
Caribbean countries/territories using AST all year:
- Anguilla
- Antigua and Barbuda
- Aruba
- Barbados
- British Virgin Islands
- Caribbean Netherlands
- Curaçao
- Dominica
- Dominican Republic
- Grenada
- Guadeloupe
- Martinique
- Montserrat
- Puerto Rico
- Saint Barthélemy
- Saint Kitts and Nevis
- Saint Lucia
- Saint Martin (FR)
- Saint Vincent and Grenadines
- Sint Maarten (NL)
- Trinidad and Tobago
- Turks and Caicos Islands
- US Virgin Islands
Other Time Zones in UTC -4
Some time zones exist that have the same offset as AST, but can be found under a different name:
AST time now
7:24:49pm
Thursday, May 23, 2019
- AST is currently observed in Santo Domingo
- AST will be observed in Halifax, Hamilton starting from Nov 3, 2019 at 2:00 am
- UTC Offset: UTC -4
- Same time as Boston
Find current time and time zone by city
Other names
AST – Tiempo Estándar del Atlántico (Spanish)
HNA – Heure Normale de l'Atlantique (French)
Other time zones named AST
Example cities
Canada – Halifax (Winter)
Canada – Blanc-Sablon (All Year)
Bermuda – Hamilton (Winter)
Dominican Republic – Santo Domingo (All Year)
Sint Maarten – Philipsburg (All Year)
Related time zones
ADT – Atlantic Daylight Time (Daylight Time)
Time Zone Map with DST
Time zones by continent/region
- Africa
- Antarctica
- Asia
- Atlantic
- Australia
- Caribbean
- Central America
- Europe
- Indian Ocean
- Military
- North America
- Pacific
- South America
See all Time zone abbreviations
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