CET
Central European Time
GMT +1
12am
3am
6am
9am
12pm
3pm
6pm
9pm
AST
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

CET is 5 hours ahead of AST. CET uses GMT +1, and AST uses GMT -4 for this comparison.

For example, 1:00 pm CET is 8:00 am AST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 2pm-5pm CET, which is 9am-12pm AST.

Compare CET time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Central European Time is 5 hours ahead of Atlantic Standard Time
1:00 pm13:00 in CET is 8:00 am08:00 in AST

CET to AST call time
Best time for a conference call or a meeting is between 2pm-5pm in CET which corresponds to 9am-12pm in AST

1:00 pm13:00 Central European Time (CET). Offset UTC +1:00 hour
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

1:00 pm13:00 CET / 8:00 am08:00 AST

CETAST
12am (midnight)7pm
1am8pm
2am9pm
3am10pm
4am11pm
5am12am (midnight)
6am1am
7am2am
8am3am
9am4am
10am5am
11am6am
12pm (noon)7am
1pm8am
2pm9am
3pm10am
4pm11am
5pm12pm (noon)
6pm1pm
7pm2pm
8pm3pm
9pm4pm
10pm5pm
11pm6pm
00:0019:00
01:0020:00
02:0021:00
03:0022:00
04:0023:00
05:0000:00
06:0001:00
07:0002:00
08:0003:00
09:0004:00
10:0005:00
11:0006:00
12:0007:00
13:0008:00
14:0009:00
15:0010:00
16:0011:00
17:0012:00
18:0013:00
19:0014:00
20:0015:00
21:0016:00
22:0017:00
23:0018:00

Central European Time

Offset: CET is 1 hour ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Andorra, Albania, Austria, Bosnia & Herzegovina, Belgium, Switzerland, Czech Republic, Germany, Denmark, Algeria, 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, Tunisia, Vatican City

Principal Cities: The largest city in the CET time zone is Berlin in Germany, with about 3.426 million people. Other major cities in this time zone include Madrid, Rome, Paris, Algiers.

German: MEZ - Mitteleuropäische Zeit

CET Time Zone Geo Map
CET timezone map

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Central European Summer Time (CEST).

Daylight saving time clock moves back for one hour from 3am to 2amStart: Central European Time (CET) started on Sunday, October 26, 2025 at 3:00 am local time and clocks were set one hour back to Sunday, October 26, 2025, 2:00 am. Standard time starts annually on the last Sunday of October.

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Central European Time (CET) ends on Sunday, March 29, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 29, 2026, 3:00 am local daylight time instead. Standard time ends annually on the last Sunday of March.

CET representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +01 - basic short
  • +0100 - basic
  • +01:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0100 - sign character (+) followed by a four digit time providing hours (01) and minutes (00) of the offset. Indicates an offset of one hour to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Alpha - Military abbreviation for CET
  • A - short form of 'Alpha'
IANA/Olson: Reflects CET time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Algiers
  • Africa/Ceuta
  • Africa/Tunis
  • 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
  • MET
  • Poland
Time zones with the GMT +1 offset:
  • BST - British Summer Time
  • CET - Central European Time
  • IST - Irish Standard Time
  • WEST - Western European Summer Time
  • A - Alpha Time Zone
  • CET - Central European Time
  • MEZ - Mitteleuropäische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time

Atlantic Standard Time

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

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 Dominican Republic, with about 2.202 million people. Other major cities in this time zone include 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 time zone. During summer, some places set clocks forward one hour for daylight saving time 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 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the 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 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the 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 an offset of four hours 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
  • HLV - Hora Legal de Venezuela
  • PYT - Paraguay Time
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time