AST
Atlantic Standard Time
GMT -4
AST is NOT in use by many locations
ADT (Atlantic Daylight Time) is used instead. Switch to ADT time zone or select one of the cities Santo Domingo, Santiago de los Caballeros, Santo Domingo Oeste for automatic timezone change.
ET/EDT
Eastern Time
GMT -4

Time Difference

Atlantic Standard Time is 0 hours ahead of Eastern Daylight Time
So 10:00 pm22:00 in AST is 10:00 pm22:00 in EDT

10:00 pm22:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
10:00 pm22:00 Eastern Daylight Time (EDT). Offset UTC -4:00 hours

10:00 pm22:00 AST / 10:00 pm22:00 EDT

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

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

Daylight Saving: This is a standard timezone, however during summer some places adjust time for one hour forward for daylight saving and observe Atlantic Daylight Time (ADT).

End: AST ends annually on the same date and time. and clocks were set one hour forward on Sunday, March 10, 2019, at 2:00 (2:00 am) local time.

Start: AST starts annually on the same date and time. and clocks are set one hour back on Sunday, November 3, 2019, at 2:00 (2:00 am) local time.

French: HNA - Heure Normale de l'Atlantique

Spanish: AST - Tiempo Estándar del Atlántico

AST Time Zone Geo Map
AST timezone map
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

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
  • PYT - Paraguay Time
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time
  • -04 -


Eastern Time

Eastern Time (ET) is a general term used to describe the areas that observe either the Eastern Standard Time (EST) or Eastern Daylight Time (EDT) in the United States and Canada. ET is not static but switches between EDT and EST.

ET is also used somewhat as a de facto official time for all of the United States because it encompasses 17 U.S. states in the eastern part of the contiguous United States including the capital city Washington D.C., the most populous city New York and half of the country’s population.

In the United States nationally televised programs, evening newscasts, talent and awards shows, and any other nationally televised event that airs live on American television during prime time and on the weekends are broadcast live in the Eastern Time Zone. Major professional sports leagues MLB, NBA, NFL and NHL also provide their game times in Eastern Time, even if teams are from outside of Eastern Time.

Countries: It is used in following countries: Bahamas, Canada, Haiti, Jamaica, Cayman Islands, Mexico, Panama, Turks & Caicos Is, United States.

Principal Cities: The largest city in the EST timezone is New York City from USA with population about 8.175 million people. Other major cities in the area are Toronto, Montreal, Brooklyn, Borough of Queens.

French: HNE - Heure Normale de l'Est

Spanish: ET - Tiempo del Este, ET - Zona Sureste

ET representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -05 - basic short
  • -0500 - basic
  • -05:00 - extended

Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0500 - sign character (-) followed by a four digit time providing hours (05) and minutes (00) of the offset. Indicates five 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
  • Romeo - Military abbreviation for ET
  • R - short form of 'Romeo'

ET Abbreviation: Several time zones share ET abbreviation and it could refer to these time zones

  • Eastern Time - UTC -5
  • Tiempo del Este - UTC -5

Time zones with the GMT -5 offset:

  • CDT - Central Daylight Time
  • EST - Eastern Standard Time
  • ET - Eastern Time
  • COT - Colombia Time
  • CST - Cuba Standard Time
  • EASST - Easter Island Summer Time
  • ECT - Ecuador Time
  • PET - Peru Time
  • R - Romeo Time Zone
  • -05 -