UTC to AST Converter
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Quick answers
Selected conversion
12:00 pm12:00 UTC (UTC+0), Oct 12, 2026 = 9:00 am09:00 ADT (UTC-3), Oct 12, 2026
UTC is 3 hours ahead of ADT.
UTC and AST examples
These examples always use UTC (UTC+0) and AST (UTC-4). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
UTC is 4 hours ahead of AST.
How the time difference changes
For most of the year, UTC is 3 hours ahead of ADT. From Nov 1, 2026 to Mar 14, 2027, UTC is 4 hours ahead of AST.
For most of the year, working hours of 9:00 am to 5:00 pm in UTC correspond to 6:00 am to 2:00 pm in ADT. At other times of the year, working hours of 9:00 am to 5:00 pm in UTC correspond to 5:00 am to 1:00 pm in AST.For most of the year, working hours of 09:00 to 17:00 in UTC correspond to 06:00 to 14:00 in ADT. At other times of the year, working hours of 09:00 to 17:00 in UTC correspond to 05:00 to 13:00 in AST.
Compare UTC time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Coordinated Universal Time is 3 hours ahead of Atlantic Daylight Time.
12:00 pm12:00 in UTC is 9:00 am09:00 in ADT
UTC to ADT call time
Best time for a conference call or a meeting is between 12pm-5pm12:00-17:00 in UTC which corresponds to 9am-2pm09:00-14:00 in ADT
12:00 pm12:00 Coordinated Universal Time (UTC). Offset UTC 0:00 hours
9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
12:00 pm12:00 UTC / 9:00 am09:00 ADT
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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Coordinated Universal Time
Offset: UTC is the same as Greenwich Mean Time (GMT).
Coordinated Universal Time (UTC) is the world time standard that regulates clocks and time. It is the successor to Greenwich Mean Time (GMT). For casual use, UTC is the same as GMT, but UTC is the standard the scientific community uses.
UTC has been the time standard commonly used across the world since 1972. It is used in many technical fields, such as aviation and meteorology, and to synchronize time across internet networks.
Today some of the lighter areas are on UTC+1 (British Summer Time, Irish Standard Time, WEST).
UTC representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for UTC
- Z - short form of 'Zulu'
- Etc/UCT
- Etc/UTC
- Etc/Universal
- Etc/Zulu
- UCT
- UTC
- Universal
- Zulu
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Coordinated Universal Time
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)
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 the lighter areas are on UTC−3 (ADT).
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).
End: Atlantic Standard Time (AST) ended 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 local daylight time instead. Standard time ends annually on the second Sunday of March.
Start: Atlantic Standard Time (AST) starts 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. Standard time starts annually on the first Sunday of November.
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
- FKT - Falkland Island Time
- GYT - Guyana Time
- HLV - Hora Legal de Venezuela
- PYT - Paraguay Time
- Q - Quebec Time Zone
- VET - Venezuelan Standard Time