AST to O Converter
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
8:00 am08:00 AST (UTC-4), Nov 4, 2026 = 10:00 am10:00 O (UTC-2), Nov 4, 2026
AST is 2 hours behind O.
AST and O examples
These examples always use AST (UTC-4) 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.
AST is 2 hours 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 AST 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.
| AST | O |
|---|---|
| 2:00am | |
| 3:00am | |
| 4:00am | |
| 5:00am | |
| 6:00am | |
| 7:00am | |
| 8:00am | |
| 9:00am | |
| 10:00am | |
| 11:00am | |
| 12:00pm | |
| 1:00pm | |
| 2:00pm | |
| 3:00pm | |
| 4:00pm | |
| 5:00pm | |
| 6:00pm | |
| 7:00pm | |
| 8:00pm | |
| 9:00pm | |
| 10:00pm | |
| 11:00pm | |
| 12:00am next day | |
| 1:00am next day | |
| 02:00 | |
| 03:00 | |
| 04:00 | |
| 05:00 | |
| 06:00 | |
| 07:00 | |
| 08:00 | |
| 09:00 | |
| 10:00 | |
| 11:00 | |
| 12:00 | |
| 13:00 | |
| 14:00 | |
| 15:00 | |
| 16:00 | |
| 17:00 | |
| 18:00 | |
| 19:00 | |
| 20:00 | |
| 21:00 | |
| 22:00 | |
| 23:00 | |
| 00:00 next day | |
| 01:00 next day |
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Anguilla, Antigua and Barbuda, Aruba, Barbados, Bermuda, British Virgin Islands, Canada, Caribbean Netherlands, Curaçao, Dominica, Dominican Republic, Greenland, Grenada, Guadeloupe, Martinique, Montserrat, Puerto Rico, Saint Barthélemy, Saint Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Maarten, Trinidad and Tobago, US Virgin Islands
Principal Cities: The largest city in the AST time zone is Santo Domingo in the Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Halifax, San Juan, San Pedro de Macorís.
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico
Today all shaded areas are on AST.
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).
Start: Atlantic Standard Time (AST) started 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. Standard time starts annually on the first Sunday of November.
End: Atlantic Standard Time (AST) ends 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 local daylight time instead. Standard time ends annually on the second Sunday of March.
See Canada daylight saving time and upcoming clock changes worldwide.
AST representations, usage and related time zones
- -04 - basic short
- -0400 - basic
- -04:00 - extended
- -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the west of the zero meridian.
- Quebec - Military abbreviation for AST
- Q - short form of 'Quebec'
- America/Anguilla
- America/Antigua
- America/Aruba
- America/Barbados
- America/Blanc-Sablon
- America/Curacao
- America/Dominica
- America/Glace_Bay
- America/Goose_Bay
- America/Grenada
- America/Guadeloupe
- America/Halifax
- America/Kralendijk
- America/Lower_Princes
- America/Marigot
- America/Martinique
- America/Moncton
- America/Montserrat
- America/Port_of_Spain
- America/Puerto_Rico
- America/Santo_Domingo
- America/St_Barthelemy
- America/St_Kitts
- America/St_Lucia
- America/St_Thomas
- America/St_Vincent
- America/Thule
- America/Tortola
- America/Virgin
- Atlantic/Bermuda
- Canada/Atlantic
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- AST - Atlantic Standard Time
- EDT - Eastern Daylight Time
- AMT - Amazon Time
- BOT - Bolivia Time
- CDT - Cuba Daylight Time
- CLT - Chile Standard Time
- GYT - Guyana Time
- HLV - Hora Legal de Venezuela
- Q - Quebec Time Zone
- VET - Venezuelan Standard 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