Updating current time…
PT
12am
3am
6am
9am
12pm
3pm
6pm
9pm
AST
UTC−4
4h ahead
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

4:00 am04:00 PT (UTC-8), Nov 2, 2026 = 8:00 am08:00 AST (UTC-4), Nov 2, 2026

PT is 4 hours behind AST.

How the time difference changes

For most of the year, PT is 3 hours behind AST Caribbean. From Nov 1, 2026 to Mar 14, 2027, PT is 4 hours behind AST Caribbean.

For most of the year, working hours of 9:00 am to 6:00 pm in PT correspond to 12:00 pm to 9:00 pm in AST Caribbean. At other times of the year, working hours of 9:00 am to 6:00 pm in PT correspond to 1:00 pm to 10:00 pm in AST Caribbean.For most of the year, working hours of 09:00 to 18:00 in PT correspond to 12:00 to 21:00 in AST Caribbean. At other times of the year, working hours of 09:00 to 18:00 in PT correspond to 13:00 to 22:00 in AST Caribbean.

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

Time Difference

Pacific Time is 4 hours behind Atlantic Standard Time.
4:00 am04:00 in PT is 8:00 am08:00 in AST

PT to AST call time
Best time for a conference call or a meeting is between 9am-2pm09:00-14:00 in PT which corresponds to 1pm-6pm13:00-18:00 in AST

4:00 am04:00 Pacific Time (PT). Offset UTC -8:00 hours
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

4:00 am04:00 PT / 8:00 am08:00 AST

Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.

Hourly time comparison
PTAST
4:00am
5:00am
6:00am
7:00am
8:00am
9:00am
10:00am
11:00am
12:00pm
1:00pm
2:00pm
3:00pm
4:00pm
5:00pm
6:00pm
7:00pm
8:00pm
9:00pm
10:00pm
11:00pm
12:00am next day
1:00am next day
2:00am next day
3:00am next day
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
00:00 next day
01:00 next day
02:00 next day
03:00 next day

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 North America. 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 United States and the Northwestern part of Mexico. From November 1, 2026, most of British Columbia in Canada keeps UTC-7 all year instead.

Countries using this time zone: Mexico, United States

Principal Cities: The largest city in the PT time zone is Los Angeles in the United States, with about 3.821 million people. Other major cities in this time zone include Tijuana, San Diego, Mexicali, 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 an offset of eight hours 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'
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).

Countries using this time zone: Anguilla, Antigua and Barbuda, Aruba, Barbados, Bermuda, British Virgin Islands, Canada, Caribbean Netherlands, Curaçao, Dominica, Dominican Republic, Greenland, Grenada, Guadeloupe, Martinique, Montserrat, Puerto Rico, Saint Barthélemy, Saint Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Maarten, Trinidad and Tobago, US Virgin Islands

Principal Cities: The largest city in the AST time zone is Santo Domingo in the Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Halifax, San Juan, San Pedro de Macorís.

Daylight Saving: Some places on Atlantic Standard Time (AST) keep the same time all year, while others use AST for only part of the year and change their clocks for daylight saving time; see upcoming clock changes worldwide.

Map of the areas on Atlantic Standard Time (AST)
AST all year AST part of the year

Today all shaded areas are on AST.

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
  • GYT - Guyana Time
  • HLV - Hora Legal de Venezuela
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time