AST/ADT
Atlantic Standard Time
GMT -4
ADT automatically adjusted to AST time zone, that is in use
HNA
Heure Normale de l'Atlantique
GMT -4

Time Difference

Atlantic Standard Time is 0 hours ahead of Heure Normale de l'Atlantique
12:00 am00:00 in AST is 12:00 am00:00 in HNA

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

12:00 am00:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
12:00 am00:00 Heure Normale de l'Atlantique (HNA). Offset UTC -4:00 hours

12:00 am00:00 AST / 12:00 am00:00 HNA

AST HNA
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 7, 2021 at 2:00 am local time and clocks were set one hour back to Sunday, November 7, 2021, 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 13, 2022 at 2:00 am local time and clocks are set one hour forward to Sunday, March 13, 2022, 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

Heure Normale de l'Atlantique

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

HNA 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 HNA
  • Q - short form of 'Quebec'
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