ADT to O Converter
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Quick answers
Selected conversion
8:00 am08:00 AST (UTC-4), Nov 3, 2026 = 10:00 am10:00 O (UTC-2), Nov 3, 2026
AST is 2 hours behind O.
ADT and O examples
These examples always use ADT (UTC-3) and O (UTC-2). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
ADT is 1 hour behind O.
How the time difference changes
For most of the year, ADT is 1 hour behind O. From Nov 1, 2026 to Mar 14, 2027, AST is 2 hours behind O.
For most of the year, working hours of 9:00 am to 6:00 pm in ADT correspond to 10:00 am to 7:00 pm in O. At other times of the year, working hours of 9:00 am to 6:00 pm in AST correspond to 11:00 am to 8:00 pm in O.For most of the year, working hours of 09:00 to 18:00 in ADT correspond to 10:00 to 19:00 in O. At other times of the year, working hours of 09:00 to 18:00 in AST correspond to 11:00 to 20:00 in O.
Compare ADT time with O time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Atlantic Standard Time is 2 hours behind Oscar Time Zone.
8:00 am08:00 in AST is 10:00 am10:00 in O
AST to O call time
Best time for a conference call or a meeting is between 9am-4pm09:00-16:00 in AST which corresponds to 11am-6pm11:00-18:00 in O
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
10:00 am10:00 Oscar Time Zone (O). Offset UTC -2:00 hours
8:00 am08:00 AST / 10:00 am10:00 O
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.
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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 the shaded areas are on UTC−4 (Atlantic Standard Time).
Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Atlantic Standard Time (AST).
End: Atlantic Daylight Time (ADT) ended on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks were 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.
Start: Atlantic Daylight Time (ADT) starts on Sunday, March 14, 2027 at 2:00 am02:00 local time and clocks are set one hour forward to Sunday, March 14, 2027, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.
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
Oscar Time Zone
Offset: O is 2 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Brazil, Greenland, Saint Pierre and Miquelon, South Georgia and the South Sandwich Islands
Principal Cities: The largest city in the O time zone is Nuuk in Greenland, with about 14,798 people. Other major cities in this time zone include Saint-Pierre, Sisimiut, Ilulissat, Qaqortoq.
Daylight Saving: Some places on Oscar Time Zone (O) keep the same time all year, while others use O for only part of the year and change their clocks for daylight saving time; see upcoming clock changes worldwide.
Today some of the lighter areas are on UTC−3.
O representations, usage and related time zones
- -02 - basic short
- -0200 - basic
- -02:00 - extended
- -0200 - sign character (-) followed by a four digit time providing hours (02) and minutes (00) of the offset. Indicates an offset of two hours to the west of the zero meridian.
- Oscar - Military abbreviation for O
- O - short form of 'Oscar'
- PMDT - Pierre & Miquelon Daylight Time
- WGT - West Greenland Time
- BRST - Brasilia Summer Time
- FNT - Fernando de Noronha Time
- O - Oscar Time Zone
- UYST - Uruguay Summer Time