ADT to HAA Converter
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Quick answers
Selected conversion
9:00 am09:00 ADT (UTC-3), Oct 28, 2026 = 9:00 am09:00 HAA (UTC-3), Oct 28, 2026
ADT and HAA have the same local time.
ADT and HAA examples
These examples always use ADT (UTC-3) and HAA (UTC-3). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
ADT and HAA have the same local time.
How the time difference changes
For most of the year, ADT and HAA have the same time. From Nov 1, 2026 to Mar 14, 2027, AST is 1 hour behind HAA.
For most of the year, working hours of 9:00 am to 6:00 pm in ADT correspond to 9:00 am to 6:00 pm in HAA. At other times of the year, working hours of 9:00 am to 6:00 pm in AST correspond to 10:00 am to 7:00 pm in HAA.For most of the year, working hours of 09:00 to 18:00 in ADT correspond to 09:00 to 18:00 in HAA. At other times of the year, working hours of 09:00 to 18:00 in AST correspond to 10:00 to 19:00 in HAA.
Compare ADT time with HAA time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Atlantic Daylight Time and Heure Avancée de l'Atlantique have the same local time.
9:00 am09:00 in ADT is 9:00 am09:00 in HAA
ADT to HAA call time
Best time for a conference call or a meeting is between 9am-6pm09:00-18:00 in ADT which corresponds to 9am-6pm09:00-18:00 in HAA
9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
9:00 am09:00 Heure Avancée de l'Atlantique (HAA). Offset UTC -3:00 hours
9:00 am09:00 ADT / 9:00 am09:00 HAA
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
| ADT | HAA |
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Atlantic Daylight Time
Offset: ADT is 3 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Bermuda, Canada, Greenland
Principal Cities: The largest city in the ADT time zone is Halifax in Canada, with about 471,559 people. Other major cities in this time zone include Sydney, Moncton, Saint John, Fredericton.
French: HAA - Heure Avancée de l'Atlantique
Today all shaded areas are on ADT.
Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Atlantic Standard Time (AST).
Start: Atlantic Daylight Time (ADT) started on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.
End: Atlantic Daylight Time (ADT) ends on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the first Sunday of November.
See Canada daylight saving time and upcoming clock changes worldwide.
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 an offset of three hours 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
- AMST - Amazon Summer Time
- ART - Argentina Time
- BRT - Brasilia Time
- CLST - Chile Summer Time
- FKST - Falkland Islands Summer Time
- FKT - Falkland Islands Time
- GFT - French Guiana Time
- P - Papa Time Zone
- PYST - Paraguay Summer Time
- PYT - Paraguay Time
- SRT - Suriname Time
- UYT - Uruguay Time
Heure Avancée de l'Atlantique
Offset: HAA is 3 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Bermuda, Canada, Greenland
Principal Cities: The largest city in the HAA time zone is Halifax in Canada, with about 471,559 people. Other major cities in this time zone include Sydney, Moncton, Saint John, Fredericton.
Today all shaded areas are on HAA.
Daylight Saving: Heure Avancée de l'Atlantique (HAA) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Atlantic Standard Time (AST).
Start: Heure Avancée de l'Atlantique (HAA) started on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.
End: Heure Avancée de l'Atlantique (HAA) ends on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the first Sunday of November.
See Canada daylight saving time and upcoming clock changes worldwide.
HAA 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 an offset of three hours to the west of the zero meridian.
- Papa - Military abbreviation for HAA
- P - short form of 'Papa'
- ADT - Atlantic Daylight Time
- PMT - Pierre & Miquelon Standard Time
- PMST - Pierre & Miquelon Standard Time
- AMST - Amazon Summer Time
- ART - Argentina Time
- BRT - Brasilia Time
- CLST - Chile Summer Time
- FKST - Falkland Islands Summer Time
- FKT - Falkland Islands Time
- GFT - French Guiana Time
- P - Papa Time Zone
- PYST - Paraguay Summer Time
- PYT - Paraguay Time
- SRT - Suriname Time
- UYT - Uruguay Time