AST
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
PST
Pacific Standard Time
GMT -8
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

AST is 4 hours ahead of PST. AST uses GMT -4, and PST uses GMT -8 for this comparison.

For example, 8:00 am AST is 4:00 am PST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 1pm-5pm AST, which is 9am-1pm PST.

PST is a fixed UTC-8 standard-time offset. For current Pacific Time, compare AST to PDT or AST to PT.

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

Time Difference

Atlantic Standard Time is 4 hours ahead of Pacific Standard Time
8:00 am08:00 in AST is 4:00 am04:00 in PST

AST to PST call time
Best time for a conference call or a meeting is between 1pm-5pm in AST which corresponds to 9am-1pm in PST

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

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

ASTPST
12am (midnight)8pm
1am9pm
2am10pm
3am11pm
4am12am (midnight)
5am1am
6am2am
7am3am
8am4am
9am5am
10am6am
11am7am
12pm (noon)8am
1pm9am
2pm10am
3pm11am
4pm12pm (noon)
5pm1pm
6pm2pm
7pm3pm
8pm4pm
9pm5pm
10pm6pm
11pm7pm
00:0020:00
01:0021:00
02:0022:00
03:0023:00
04:0000:00
05:0001:00
06:0002:00
07:0003:00
08:0004:00
09:0005:00
10:0006:00
11:0007:00
12:0008:00
13:0009:00
14:0010:00
15:0011:00
16:0012:00
17:0013:00
18:0014:00
19:0015:00
20:0016:00
21:0017:00
22:0018:00
23:0019:00

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

Pacific Standard Time

Offset: PST is 8 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Canada, Mexico, United States

Principal Cities: The largest city in the PST time zone is Los Angeles in the United States, with about 3.793 million people. Other major cities in this time zone include Vancouver, Tijuana, San Diego, San Jose.

French: HNP - Heure Normale du Pacifique

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

PST Time Zone Geo Map
PST 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 Pacific Daylight Time (PDT).

Daylight saving time clock moves back for one hour from 2am to 1amStart: Pacific Standard Time (PST) 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: Pacific Standard Time (PST) 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.

PST 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 PST
  • U - short form of 'Uniform'
IANA/Olson: Reflects PST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Ensenada
  • America/Los_Angeles
  • America/Santa_Isabel
  • America/Tijuana
  • America/Vancouver
  • Canada/Pacific
  • Mexico/BajaNorte
  • PST8PDT
  • US/Pacific
PST Abbreviation: Several time zones share PST abbreviation and it could refer to these time zones
  • Pacific Standard Time - UTC -8
  • Pitcairn Standard Time - UTC -8
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