ADT/AST
Atlantic Daylight Time
GMT -3
AST automatically adjusted to ADT time zone, that is in use
BST
British Summer Time
GMT +1

Time Difference

Atlantic Daylight Time is 4 hours behind British Summer Time
6:00 am06:00 in ADT is 10:00 am10:00 in BST

AST to BST call time
Best time for a conference call or a meeting is between 8am-1pm in AST which corresponds to 1pm-6pm in BST

6:00 am06:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
10:00 am10:00 British Summer Time (BST). Offset UTC +1:00 hour

6:00 am06:00 ADT / 10:00 am10:00 BST

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

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 time zone, 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 forward for one hour from 2am to 3amEnd: Atlantic Standard Time (AST) has ended on Sunday, March 10, 2024 at 2:00 am local time and clocks were set one hour forward to Sunday, March 10, 2024, 3:00 am local daylight time instead. Standard time ends annually the on second Sunday of March.

Daylight saving time clock moves back for one hour from 2am to 1amStart: Atlantic Standard Time (AST) starts on Sunday, November 3, 2024 at 2:00 am local time and clocks are set one hour back to Sunday, November 3, 2024, 1:00 am. Standard time starts annually the on first Sunday of November.

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

British Summer Time

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

Countries: It is used in following countries: Britain (UK), Guernsey, Isle of Man, Jersey

Principal Cities: The largest city in the BST timezone is London from United Kingdom with population about 7.557 million people. Other major cities in the area are Birmingham, Glasgow, Liverpool, Saint Helier

BST Time Zone Geo Map
BST timezone map

Daylight Saving: British Summer Time (BST) is a daylight saving/summer timezone, however during winter some places switch clocks for one hour back and observe Greenwich Mean Time (GMT).

Daylight saving time clock moves forward for one hour from 1am to 2amStart: British Summer Time (BST) started on Sunday, March 31, 2024 at 1:00 am local time and clocks were set one hour forward to Sunday, March 31, 2024, 2:00 am. Daylight saving starts annually the on last Sunday of March

Daylight saving time clock moves back for one hour from 2am to 1amEnd: British Summer Time (BST) ends on Sunday, October 27, 2024 at 2:00 am local time and clocks are set one hour back to Sunday, October 27, 2024, 1:00 am local standard time instead. Daylight saving ends annually the on last Sunday of October

BST 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 one 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
  • Alpha - Military abbreviation for BST
  • A - short form of 'Alpha'
IANA/Olson: Reflects BST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Europe/Belfast
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire
BST Abbreviation: Several time zones share BST abbreviation and it could refer to these time zones
  • British Summer Time - UTC +1
  • Bangladesh Standard Time - UTC +6
  • Bougainville Standard Time - UTC +11
  • Brasilia Standard Time - UTC -3
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