AST/ADT
Atlantic Standard Time
GMT -4
ADT automatically adjusted to AST time zone, that is in use
-04
GMT -4
-04 is NOT in use by many locations
-03 () is used instead. Switch to -03 time zone or select one of the cities Santiago, Caracas, Maracaibo) for automatic timezone change.

Time Difference

Atlantic Standard Time is 0 hours ahead of
6:00 am06:00 in AST is 6:00 am06:00 in -04

ADT to -04 call time
Best time for a conference call or a meeting is between 9am-6pm in ADT which corresponds to 8am-5pm in -04

6:00 am06:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
6:00 am06:00 (-04). Offset UTC -4:00 hours

6:00 am06:00 AST / 6:00 am06:00 -04

AST -04
12am (midnight) 12am (midnight)
1am 1am
2am 2am
3am 3am
4am 4am
5am 5am
6am 6am
7am 7am
8am 8am
9am 9am
10am 10am
11am 11am
12pm (noon) 12pm (noon)
1pm 1pm
2pm 2pm
3pm 3pm
4pm 4pm
5pm 5pm
6pm 6pm
7pm 7pm
8pm 8pm
9pm 9pm
10pm 10pm
11pm 11pm
0:00 0:00
1:00 1:00
2:00 2:00
3:00 3:00
4:00 4:00
5:00 5:00
6:00 6:00
7:00 7:00
8:00 8:00
9:00 9:00
10:00 10:00
11:00 11:00
12:00 12:00
13:00 13:00
14:00 14:00
15:00 15:00
16:00 16:00
17:00 17:00
18:00 18:00
19:00 19:00
20:00 20:00
21:00 21:00
22:00 22:00
23:00 23:00

Atlantic Daylight Time

Offset: ADT is 3 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries: It is used in following countries: Bermuda, Canada, Greenland

Principal Cities: The largest city in the ADT timezone is Halifax from Canada with population about 359,111 people. Other major cities in the area are Sydney, Dartmouth, Saint John, Moncton

French: HAA - Heure Avancée de l'Atlantique

ADT Time Zone Geo Map
ADT timezone map

Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone, however during winter some places adjust time for one hour back and observe Atlantic Standard Time (AST).

Daylight saving time clock moves back for one hour from 2am to 1amEnd: Atlantic Daylight Time (ADT) has ended on Sunday, November 6, 2022 at 2:00 am local time and clocks were 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

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Atlantic Daylight Time (ADT) starts on Sunday, March 12, 2023 at 2:00 am local time and clocks are set one hour forward to Sunday, March 12, 2023, 3:00 am. Daylight saving starts annually the on second Sunday of March

ADT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -03 - basic short
  • -0300 - basic
  • -03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates three 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
  • Papa - Military abbreviation for ADT
  • P - short form of 'Papa'
IANA/Olson: Reflects ADT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Halifax
  • America/Moncton
  • America/Thule
  • Atlantic/Bermuda
  • Canada/Atlantic
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • WGT - West Greenland Time
  • AMST - Amazon Summer Time
  • ART - Argentina Time
  • BRT - Brasília time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • SRT - Suriname Time
  • UYT - Uruguay Time

-04

Offset: -04 is 4 hours behind Greenwich Mean Time (GMT) and is used in America

Countries: It is used in following countries: Bolivia, Brazil, Chile, Guyana, Paraguay, Venezuela

Principal Cities: The largest city in the -04 timezone is Santiago from Chile with population about 4.837 million people. Other major cities in the area are Caracas, Maracaibo, Maracay, Manaus

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 (-03).

Daylight saving time clock moves forward for one hour from 12am to 1amEnd: (-04) has ended on Sunday, October 2, 2022 at 12:00 am local time and clocks were set one hour forward to Sunday, October 2, 2022, 1:00 am local daylight time instead. Standard time ends .

Daylight saving time clock moves back for one hour from 12am to 11pmStart: (-04) starts on Sunday, March 26, 2023 at 12:00 am local time and clocks are set one hour back to Saturday, March 25, 2023, 11:00 pm. Standard time starts .

-04 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 -04
  • Q - short form of 'Quebec'
IANA/Olson: Reflects -04 time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Asuncion
  • America/Boa_Vista
  • America/Campo_Grande
  • America/Caracas
  • America/Cuiaba
  • America/Guyana
  • America/La_Paz
  • America/Manaus
  • America/Porto_Velho
  • America/Santiago
  • Brazil/West
  • Chile/Continental
  • Etc/GMT+4
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