ADT Converter
Atlantic Daylight Time
Offset: ADT is 3 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries: It is used in following countries: Bermuda, Canada, Greenland
Principal Cities: The largest city in the ADT timezone is Halifax from Canada with population about 359,111 people. Other major cities in the area are Sydney, Dartmouth, Saint John, Moncton
French: HAA - Heure Avancée de l'Atlantique

Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer timezone, however during winter some places switch clocks for one hour back and observe Atlantic Standard Time (AST).
Start: Atlantic Daylight Time (ADT) started on Sunday, March 9, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, March 9, 2025, 3:00 am. Daylight saving starts annually the on second Sunday of March
End: Atlantic Daylight Time (ADT) ends on Sunday, November 2, 2025 at 2:00 am local time and clocks are set one hour back to Sunday, November 2, 2025, 1:00 am local standard time instead. Daylight saving ends annually the on first Sunday of November
ADT representations, usage and related time zones
- -03 - basic short
- -0300 - basic
- -03:00 - extended
- -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates three hour and zero minutes time differences to the west of the zero meridian.
- Papa - Military abbreviation for ADT
- P - short form of 'Papa'
- America/Glace_Bay
- America/Goose_Bay
- America/Halifax
- America/Moncton
- America/Thule
- Atlantic/Bermuda
- Canada/Atlantic
- ADT - Atlantic Daylight Time
- PMT - Pierre & Miquelon Standard Time
- PMST - Pierre & Miquelon Standard Time
- WGT - West Greenland Time
- AMST - Amazon Summer Time
- ART - Argentina Time
- BRT - BrasÃlia time
- CLST - Chile Summer Time
- FKST - Falkland Islands Summer Time
- GFT - French Guiana Time
- P - Papa Time Zone
- PYST - Paraguay Summer Time
- SRT - Suriname Time
- UYT - Uruguay Time