Atlantic Time Zone - AT

Atlantic Time is a blanket term used to describe multiple time zones including Atlantic Daylight Time (ADT) and Atlantic Standard Time (AST).

Atlantic Daylight Time

Atlantic Daylight Time or ADT has a UTC offset of - 3:00. This means that the time zone is 3 hours behind Coordinated Universal Time. The time zone is primarily observed by areas of North America, and the Caribbean during the summer months when Daylight Saving is active.

Atlantic Standard Time

Atlantic Standard Time or AST has a UTC offset of - 4:00. This means that the time zone is 4 hours behind Coordinated Universal Time. The time zone is primarily observed by areas of North America, and the Caribbean during the winter months when Daylight Saving is inactive.

Locations in Atlantic Time Zone

These time zones are active in:

• North America

  • Canada

    • Mainland Labrador and Newfoundland

    • New Brunswick

    • Nova Scotia

    • Prince Edward Island

    • Quebec

  • Greenland

    • Thule area

  • Caribbean

    • Anguilla

    • Antigua and Barbuda

    • Aruba

    • Barbados

    • Bermuda

    • Bonaire

    • British Virgin Islands

    • Curacao

    • Dominica

    • Dominican Republic

    • France

    • Grenada

    • Guadeloupe

    • Martinique

    • Montserrat

    • Puerto Rico

    • Saint Kitts and Nevis

    • Saint Lucia

    • Saint Vincent and Grenadines

    • Sint Maarten

    • Trinidad and Tobago

    • Turks and Caicos Islands

    • US Virgin Islands

All the Caribbean listed above except for Bermuda, remain on Atlantic Standard Time (AST) all year long and do not observe Daylight Saving. The Canadian province of Quebec also remains on AST all year long.