PST/PDT
Pacific Standard Time
GMT -8
12am
3am
6am
9am
12pm
3pm
6pm
9pm
PDT is not used on this date
This converter uses PST (GMT -8), the offset Los Angeles uses on this date. Open the PST converter.
AST
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm

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

Time Difference

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

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

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

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

PSTAST
12am (midnight)4am
1am5am
2am6am
3am7am
4am8am
5am9am
6am10am
7am11am
8am12pm (noon)
9am1pm
10am2pm
11am3pm
12pm (noon)4pm
1pm5pm
2pm6pm
3pm7pm
4pm8pm
5pm9pm
6pm10pm
7pm11pm
8pm12am (midnight)
9pm1am
10pm2am
11pm3am
00:0004:00
01:0005:00
02:0006:00
03:0007:00
04:0008:00
05:0009:00
06:0010:00
07:0011:00
08:0012:00
09:0013:00
10:0014:00
11:0015:00
12:0016:00
13:0017:00
14:0018:00
15:0019:00
16:0020:00
17:0021:00
18:0022:00
19:0023:00
20:0000:00
21:0001:00
22:0002:00
23:0003:00

Pacific Daylight Time

Offset: PDT is 7 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 PDT 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: HAP - Heure Avancée du Pacifique

Spanish: PT - Zona Noroeste

PDT Time Zone Geo Map
PDT timezone map

Daylight Saving: Pacific Daylight Time (PDT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Pacific Standard Time (PST).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Pacific Daylight Time (PDT) ended 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 local standard time instead. Daylight saving ends annually on the first Sunday of November

Daylight saving time clock moves back for one hour from 2am to 1amStart: Pacific Daylight Time (PDT) starts 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. Daylight saving starts annually on the second Sunday of March

PDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -07 - basic short
  • -0700 - basic
  • -07:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0700 - sign character (-) followed by a four digit time providing hours (07) and minutes (00) of the offset. Indicates an offset of seven hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Tango - Military abbreviation for PDT
  • T - short form of 'Tango'
IANA/Olson: Reflects PDT 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
Time zones with the GMT -7 offset:
  • MST - Mountain Standard Time
  • PDT - Pacific Daylight Time
  • YST - Yukon Standard Time
  • T - Tango Time Zone

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