PT/PDT
Pacific Time
GMT -7
ADT/AST
Atlantic Daylight Time
GMT -3
AST automatically adjusted to ADT time zone, that is in use

Time Difference

Pacific Daylight Time is 4 hours behind Atlantic Daylight Time
11:30 pm23:30 in PDT is 3:30 am03:30 in ADT

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

11:30 pm23:30 Pacific Daylight Time (PDT). Offset UTC -7:00 hours
3:30 am03:30 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours

11:30 pm23:30 PDT / 3:30 am03:30 ADT

PT ADT
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

Pacific Time

Pacific Time (PT) is a general term used to describe the areas that observe either the Pacific Standard Time (PST) or Pacific Daylight Time (PDT) in the United States and Canada. PT also called Pacific Coast Time. PT is not static but switches between PDT and PST.

Territories observing the Pacific Time Zone are primarily in North America. It runs through the western part of Canada, the United States and the Northwestern part of Mexico.

Countries: It is used in following countries: Canada, Mexico, United States.

Principal Cities: The largest city in the PST timezone is Los Angeles from USA with population about 3.793 million people. Other major cities in the area are Vancouver, Tijuana, San Diego, San Jose.

French: HNP - Heure Normale du Pacifique

Spanish: PT - Tiempo del Pacífico, PT - Zona Noroeste

Pacific Time (PT) is a general term used to describe the areas that observe either the Pacific Standard Time (PST) or Pacific Daylight Time (PDT) in the United States and Canada. PT also called Pacific Coast Time. PT is not static but switches between PDT and PST.

Territories observing the Pacific Time Zone are primarily in North America. It runs through the western part of Canada, the United States and the Northwestern part of Mexico.

Countries: It is used in following countries: Canada, Mexico, United States.

Principal Cities: The largest city in the PST timezone is Los Angeles from USA with population about 3.793 million people. Other major cities in the area are Vancouver, Tijuana, San Diego, San Jose.

French: HNP - Heure Normale du Pacifique

Spanish: PT - Tiempo del Pacífico, PT - Zona Noroeste

PT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -08 - basic short
  • -0800 - basic
  • -08:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0800 - sign character (-) followed by a four digit time providing hours (08) and minutes (00) of the offset. Indicates eight 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
  • Uniform - Military abbreviation for PT
  • U - short form of 'Uniform'
PT Abbreviation: Several time zones share PT abbreviation and it could refer to these time zones
  • Pacific Time - UTC -8
  • Palau Time - UTC +9
Time zones with the GMT -8 offset:
  • AKDT - Alaska Daylight Time
  • PST - Pacific Standard Time
  • PT - Pacific Time
  • PST - Pitcairn Standard Time
  • U - Uniform 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 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