UTC
Universal Time Coordinated
GMT +0
AST
Atlantic Standard Time
GMT -4

Time Difference

Universal Time Coordinated is 4 hours ahead of Atlantic Standard Time
5:00 pm17:00 in UTC is 1:00 pm13:00 in AST

UTC to AST call time
Best time for a conference call or a meeting is between 12pm-6pm in UTC which corresponds to 8am-2pm in AST

5:00 pm17:00 Universal Time Coordinated (UTC). Offset UTC 0:00 hours
1:00 pm13:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

5:00 pm17:00 UTC / 1:00 pm13:00 AST

UTC AST
12am (midnight) 8pm
1am 9pm
2am 10pm
3am 11pm
4am 12am (midnight)
5am 1am
6am 2am
7am 3am
8am 4am
9am 5am
10am 6am
11am 7am
12pm (noon) 8am
1pm 9am
2pm 10am
3pm 11am
4pm 12pm (noon)
5pm 1pm
6pm 2pm
7pm 3pm
8pm 4pm
9pm 5pm
10pm 6pm
11pm 7pm
0:00 20:00
1:00 21:00
2:00 22:00
3:00 23:00
4:00 0:00
5:00 1:00
6:00 2:00
7:00 3:00
8:00 4:00
9:00 5:00
10:00 6:00
11:00 7:00
12:00 8:00
13:00 9:00
14:00 10:00
15:00 11:00
16:00 12:00
17:00 13:00
18:00 14:00
19:00 15:00
20:00 16:00
21:00 17:00
22:00 18:00
23:00 19:00

Universal Time Coordinated

Offset: UTC is 0 hours ahead Greenwich Mean Time (GMT) and is used in Universal

Coordinated Universal Time (UTC) is the world time standard that regulates clocks and time. It is successor to Greenwich Mean Time (GMT). For casual use, UTC is the same as GMT, but is used by the scientific community.
UTC is the time standard commonly used across the world since 1972. It is used in many technical fields, like aviation industry and meteorologists, also used to synchronize time across internet networks.

UTC representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
  • +00 - basic short
  • +0000 - basic
  • +00:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates zero hour and zero minutes time differences of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for UTC
  • Z - short form of 'Zulu'
IANA/Olson: Reflects UTC time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Etc/UCT
  • Etc/UTC
  • Etc/Universal
  • Etc/Zulu
  • UCT
  • UTC
  • Universal
  • Zulu
Time zones with the GMT +0 offset:
  • EGST - Eastern Greenland Summer Time
  • GMT - Greenwich Mean Time
  • WET - Western European Time
  • AZOST - Azores Summer Time
  • UTC - Universal Time Coordinated
  • WT - Western Sahara Standard Time
  • Z - Zulu Time Zone

Atlantic Standard Time

Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries: It is used in following countries: 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 timezone is Santo Domingo from Dominican Republic with population about 2.202 million people. Other major cities in the area are Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax

French: HNA - Heure Normale de l'Atlantique

Spanish: AST - Tiempo Estándar del Atlántico

AST Time Zone Geo Map
AST timezone map

Daylight Saving: This is a standard timezone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Atlantic Daylight Time (ADT).

Daylight saving time clock moves back for one hour from 2am to 1amStart: Atlantic Standard Time (AST) started on Sunday, November 6, 2022 at 2:00 am local time and clocks were set one hour back to Sunday, November 6, 2022, 1:00 am. Standard time starts annually the on first Sunday of November.

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Atlantic Standard Time (AST) ends on Sunday, March 12, 2023 at 2:00 am local time and clocks are set one hour forward to Sunday, March 12, 2023, 3:00 am local daylight time instead. Standard time starts annually the on second Sunday of March.

AST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -04 - basic short
  • -0400 - basic
  • -04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates four hour and zero minutes time differences to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Quebec - Military abbreviation for AST
  • Q - short form of 'Quebec'
IANA/Olson: Reflects AST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • 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
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
  • Atlantic Standard Time - UTC -4
  • Arabia Standard Time - UTC +3
  • Argentina Standard Time - UTC -3
  • Arabian Standard Time - UTC +3
  • Apia Standard Time - UTC +13
  • Azores Summer Time - UTC +0
Time zones with the GMT -4 offset:
  • 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