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AT – Atlantic Time

Time Zone names, codes and abbreviations for Standard Time and Daylight Saving Time (DST) around the world.

Time zone map of AST
Currently observing AST.
Areas with same time currently (UTC -4).
Currently observing AST – Atlantic Standard Time.
Currently has same time zone offset as AST (UTC -4) but different time zone name.

The term Atlantic Time (AT) is often used to denote the local time in areas observing either Atlantic Standard Time (AST) or Atlantic Daylight Time (ADT).

Atlantic Standard Time is 4 hours behind Coordinated Universal Time (UTC).

Atlantic Daylight Time is 3 hours behind UTC.

In locations observing Daylight Saving Time (DST) during part of the year, Atlantic Time is not static but switches between AST and ADT.

See full time zone map

Where and when is Atlantic Time 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

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

AST all year round

Some locations, such as the ones below don't switch and are in AST all year long.

North America

Canadian provinces using AST all year

  • Quebec - East of 63 West only.

Caribbean

Caribbean countries/territories using AST all year

  • Anguilla
  • Antigua and Barbuda
  • Aruba
  • Barbados
  • British Virgin Islands
  • Caribbean NetherlandsShow

    Bonaire, Sint Eustatius, Saba

  • 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