Atlantic Standard Time (AST) is a time zone that is UTC −4:00, meaning it is 4 hours behind Coordinated Universal Time. It is used in parts of Canada, the Caribbean, and the Atlantic region. Some locations observe daylight saving time, while others remain on AST all year.
Current AST Time
Atlantic Standard Time is commonly used in regions such as Puerto Rico, the Dominican Republic, and parts of Canada. It serves as a key time zone for business, travel, and communication across the Atlantic region.
Quick Facts
- Time Standard: Atlantic Standard Time (AST)
- Offset: UTC −04:00
- Daylight Saving Time: Not observed in some regions (e.g., Puerto Rico), observed in others
- Used By: Parts of Canada, Caribbean countries, Atlantic regions
- Also Known As: AST
Time Difference From AST
Atlantic Standard Time is 4 hours behind UTC. Other time zones are calculated relative to AST.
Examples:
- New York: Same as AST (winter), UTC −5 / UTC −4 (summer)
- London: AST +4 hours (UTC +0 / +1 DST)
- Sydney: AST +15 hours (UTC +10 / +11 DST)
Daylight Saving Time
Some regions using Atlantic Time observe daylight saving time and switch to Atlantic Daylight Time (ADT), UTC −3:00.
However, places like Puerto Rico and most Caribbean countries do not observe DST, so they stay on AST year-round.
Best Time to Coordinate International Meetings
Atlantic Standard Time works well for coordinating between North America and parts of Europe.
For example:
09:00 AST may correspond to early morning in North America and afternoon in Europe.
Frequently Asked Questions
What does AST stand for?
AST stands for Atlantic Standard Time.
Where is AST used?
AST is used in parts of Canada and many Caribbean countries.
Does AST change during daylight saving time?
Some regions switch to ADT (UTC −3), while others remain on AST all year.
Where AST Is Used
Atlantic Standard Time is used in:
- Parts of eastern Canada (e.g., Nova Scotia, New Brunswick)
- Puerto Rico
- Dominican Republic
- U.S. Virgin Islands
- Several Caribbean islands
