PDT
Pacific Daylight 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
6:30 pm18:30 in PDT is 10:30 pm22:30 in ADT

PDT to AST call time
Best time for a conference call or a meeting is between 8am-3pm in PDT which corresponds to 11am-6pm in AST

6:30 pm18:30 Pacific Daylight Time (PDT). Offset UTC -7:00 hours
10:30 pm22:30 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours

6:30 pm18:30 PDT / 10:30 pm22:30 ADT

PDT 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 Daylight Time

Offset: PDT is 7 hours behind Greenwich Mean Time (GMT) and is used in North America

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

Principal Cities: The largest city in the PDT 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: 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 timezone, however during winter some places switch clocks for one hour back and observe Pacific Standard Time (PST).

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Pacific Daylight Time (PDT) started on Sunday, March 13, 2022 at 2:00 am local time and clocks were set one hour forward to Sunday, March 13, 2022, 3:00 am. Daylight saving starts annually the on second Sunday of March

Daylight saving time clock moves back for one hour from 2am to 1amEnd: Pacific Daylight Time (PDT) ends on Sunday, November 6, 2022 at 2:00 am local time and clocks are set one hour back to Sunday, November 6, 2022, 1:00 am local standard time instead. Daylight saving ends annually the on first Sunday of November

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 seven 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
  • 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: 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 13, 2022 at 2:00 am local time and clocks were set one hour forward to Sunday, March 13, 2022, 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 6, 2022 at 2:00 am local time and clocks are set one hour back to Sunday, November 6, 2022, 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
  • Amazon Standard Time - UTC -4
  • Azores Summer Time - UTC +0
  • 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