Atlantic Daylight Time (ADT)
Atlantic Daylight Time (ADT) is UTC−3. It is the daylight saving (summer) time of Atlantic Canada during daylight saving time; in winter the area returns to AST (UTC−4).
ADT is not in force right now – the zone is currently on AST (UTC−4).
Convert ADT
Where ADT is used
Atlantic Canada during daylight saving time.
Countries on the same offsets
Major cities on America/Halifax
ADT and daylight saving time
The next change is on 14 March 2027 at 01:59 local time: clocks go forward one hour, from AST (UTC−4) to ADT (UTC−3).
ADT FAQ
What is ADT?
Atlantic Daylight Time (ADT) is UTC−3. It is the daylight saving (summer) time of Atlantic Canada during daylight saving time; in winter the area returns to AST (UTC−4).
What is the current ADT time?
ADT is UTC−3. The live clock on this page shows the current Atlantic Daylight Time time, updated every second.
What is the difference between ADT and AST?
AST is one hour behind ADT. ADT is used during daylight saving time; AST is the standard time.
Which countries use ADT?
ADT is used in Atlantic Canada during daylight saving time.
Updated 6 November 2026. Time zone data: IANA tz database.