AST
Atlantic Standard Time
GMT -4
CET/CEST
Central European Time
GMT +1
CEST automatically adjusted to CET time zone, that is in use

Time Difference

Atlantic Standard Time is 5 hours behind Central European Time
12:00 pm12:00 in AST is 5:00 pm17:00 in CET

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

12:00 pm12:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
5:00 pm17:00 Central European Time (CET). Offset UTC +1:00 hour

12:00 pm12:00 AST / 5:00 pm17:00 CET

AST CET
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 12am (midnight)
8pm 1am
9pm 2am
10pm 3am
11pm 4am
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 0:00
20:00 1:00
21:00 2:00
22:00 3:00
23:00 4:00

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

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 7, 2021 at 2:00 am local time and clocks were set one hour back to Sunday, November 7, 2021, 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 13, 2022 at 2:00 am local time and clocks are set one hour forward to Sunday, March 13, 2022, 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
  • Arabian Standard Time - UTC +3
  • Acre Standard Time - UTC -5
  • Azores Standard Time - UTC -1
  • Apia Standard Time - UTC +13
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

Central European Summer Time

Offset: CEST is 2 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries: It is used in following countries: Andorra, Albania, Austria, Bosnia & Herzegovina, Belgium, Switzerland, Czech Republic, Germany, Denmark, Spain, France, Gibraltar, Croatia, Hungary, Italy, Liechtenstein, Luxembourg, Monaco, Montenegro, North Macedonia, Malta, Netherlands, Norway, Poland, Serbia, Sweden, Slovenia, Svalbard & Jan Mayen, Slovakia, San Marino, Vatican City

Principal Cities: The largest city in the CEST timezone is Berlin from Germany with population about 3.426 million people. Other major cities in the area are Madrid, Rome, Paris, Budapest

German: MESZ - Mitteleuropäische Sommerzeit

CEST Time Zone Geo Map
CEST timezone map

Daylight Saving: Central European Summer Time (CEST) is a daylight saving/summer time zone, however during winter some places adjust time for one hour back and observe Central European Time (CET).

Daylight saving time clock moves back for one hour from 3am to 2amEnd: Central European Summer Time (CEST) has ended on Sunday, October 31, 2021 at 3:00 am local time and clocks were set one hour back to Sunday, October 31, 2021, 2:00 am local standard time instead. Daylight saving ends annually the on last Sunday of October

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Central European Summer Time (CEST) starts on Sunday, March 27, 2022 at 2:00 am local time and clocks are set one hour forward to Sunday, March 27, 2022, 3:00 am. Daylight saving starts annually the on last Sunday of March

CEST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +02 - basic short
  • +0200 - basic
  • +02:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0200 - sign character (+) followed by a four digit time providing hours (02) and minutes (00) of the offset. Indicates two hour and zero minutes time differences to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Bravo - Military abbreviation for CEST
  • B - short form of 'Bravo'
IANA/Olson: Reflects CEST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Ceuta
  • Arctic/Longyearbyen
  • Atlantic/Jan_Mayen
  • CET
  • Europe/Amsterdam
  • Europe/Andorra
  • Europe/Belgrade
  • Europe/Berlin
  • Europe/Bratislava
  • Europe/Brussels
  • Europe/Budapest
  • Europe/Busingen
  • Europe/Copenhagen
  • Europe/Gibraltar
  • Europe/Ljubljana
  • Europe/Luxembourg
  • Europe/Madrid
  • Europe/Malta
  • Europe/Monaco
  • Europe/Oslo
  • Europe/Paris
  • Europe/Podgorica
  • Europe/Prague
  • Europe/Rome
  • Europe/San_Marino
  • Europe/Sarajevo
  • Europe/Skopje
  • Europe/Stockholm
  • Europe/Tirane
  • Europe/Vaduz
  • Europe/Vatican
  • Europe/Vienna
  • Europe/Warsaw
  • Europe/Zagreb
  • Europe/Zurich
  • Poland
Time zones with the GMT +2 offset:
  • CEST - Central European Summer Time
  • EET - Eastern European Time
  • MESZ - Mitteleuropäische Sommerzeit
  • B - Bravo Time Zone
  • CAT - Central Africa Time
  • IST - Israel Standard Time
  • SAST - South Africa Standard Time
  • WAST - West Africa Summer Time