ADT – Atlantic Daylight Time / Atlantic Daylight Saving Time (Daylight Saving Time)
Also known as: ADST – Atlantic Daylight Saving Time, AST – Atlantic Summer Time
ADT is currently not used at all
North America, Atlantic: ADT is currently not observed because locations are on standard time and are observing AST.
Observes ADT part of the year.
Areas with same time currently (UTC -3).
Observes ADT – Atlantic Daylight Time part of the year, but not currently.
Currently has same time zone offset as ADT (UTC -3) but different time zone name.
Atlantic Daylight Time (ADT) is 3 hours behind Coordinated Universal Time. This time zone is a Daylight Saving Time time zone and is used in: North America, Atlantic.
This time zone is often called ADT Time Zone.
Winter Time & DST
This time zone is a daylight saving/summer time zone, in the winter some places will switch to the corresponding standard time zone: AST (Atlantic Standard Time).
Email time zone indicator: -0300
An email sent from someone in the Atlantic Daylight Time (ADT) time zone will have the time zone listed as "-0300" in the headers of the email. (However, "-0300" does not have to be in Atlantic Daylight Time, as other time zones could have the same UTC offset).
Where and when is ADT observed?
North America
Canadian provinces using ADT in the summer and AST in the winter
- Most of Labrador (mainland part of the province of Newfoundland and Labrador)
- New Brunswick
- Nova Scotia
- Prince Edward Island
Areas of Greenland using ADT in the summer and AST in the winter
- Thule area
Atlantic
Atlantic islands/territories using ADT in the summer and AST in the winter
- Bermuda
Other time zones in UTC -3
Some time zones exist that have the same offset as ADT, but can be found under a different name:
- AMST – Amazon Summer Time
- ART – Argentina Time
- BRT – Brasília Time
- CLST – Chile Summer Time
- CLT – Chile Standard Time
- FKST – Falkland Islands Summer Time
- GFT – French Guiana Time
- P – Papa Time Zone
- PMST – Pierre & Miquelon Standard Time
- PYST – Paraguay Summer Time
- ROTT – Rothera Time
- SRT – Suriname Time
- UYT – Uruguay Time
- WARST – Western Argentine Summer Time
- WGT – West Greenland Time
No locations currently on ADT
Find current time and time zone by city
Other names
HAA – Heure Avancée de l'Atlantique (French)
Other time zones named ADT
Example cities
Canada – Halifax (Summer)
Bermuda – Hamilton (Summer)
Related time zones
AST – Atlantic Standard Time (Standard Time)
Time Zone Map with DST
Share this page / Follow us on:
Visit us on: