HAST/HADT
Hawaii-Aleutian Standard Time
GMT -10
12am
3am
6am
9am
12pm
3pm
6pm
9pm
HADT is not used on this date
This converter uses HAST (GMT -10), the offset Adak uses on this date.
GMT
Greenwich Mean Time
GMT +0
12am
3am
6am
9am
12pm
3pm
6pm
9pm

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

Time Difference

Hawaii-Aleutian Standard Time is 10 hours behind Greenwich Mean Time
2:00 am02:00 in HAST is 12:00 pm12:00 in GMT

HAST to GMT call time
Best time for a conference call or a meeting is between 7:30am-8:30am in HAST which corresponds to 5:30pm-6:30pm in GMT

2:00 am02:00 Hawaii-Aleutian Standard Time (HAST). Offset UTC -10:00 hours
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours

2:00 am02:00 HAST / 12:00 pm12:00 GMT

HASTGMT
12am (midnight)10am
1am11am
2am12pm (noon)
3am1pm
4am2pm
5am3pm
6am4pm
7am5pm
8am6pm
9am7pm
10am8pm
11am9pm
12pm (noon)10pm
1pm11pm
2pm12am (midnight)
3pm1am
4pm2am
5pm3am
6pm4am
7pm5am
8pm6am
9pm7am
10pm8am
11pm9am
00:0010:00
01:0011:00
02:0012:00
03:0013:00
04:0014:00
05:0015:00
06:0016:00
07:0017:00
08:0018:00
09:0019:00
10:0020:00
11:0021:00
12:0022:00
13:0023:00
14:0000:00
15:0001:00
16:0002:00
17:0003:00
18:0004:00
19:0005:00
20:0006:00
21:0007:00
22:0008:00
23:0009:00

Hawaii-Aleutian Daylight Time

Offset: HADT is 9 hours behind Greenwich Mean Time (GMT) and is used in North America

Daylight Saving: Hawaii-Aleutian Daylight Time (HADT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Hawaii-Aleutian Standard Time (HAST).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Hawaii-Aleutian Daylight Time (HADT) 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: Hawaii-Aleutian Daylight Time (HADT) 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

HADT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -09 - basic short
  • -0900 - basic
  • -09:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0900 - sign character (-) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates an offset of nine hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Victor - Military abbreviation for HADT
  • V - short form of 'Victor'
Time zones with the GMT -9 offset:
  • AKST - Alaska Standard Time
  • AHDT - Alaska-Hawaii Daylight Time
  • HADT - Hawaii-Aleutian Daylight Time
  • GAMT - Gambier Time
  • HDT - Hawaii Daylight Time
  • V - Victor Time Zone

Greenwich Mean Time

Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo

Principal Cities: The largest city in the GMT time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Abidjan, Dakar, Grand Dakar, Accra.

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.

GMT Time Zone Geo Map
GMT timezone map

GMT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
  • +00 - basic short
  • +0000 - basic
  • +00:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for GMT
  • Z - short form of 'Zulu'
IANA/Olson: Reflects GMT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Abidjan
  • Africa/Accra
  • Africa/Bamako
  • Africa/Banjul
  • Africa/Bissau
  • Africa/Conakry
  • Africa/Dakar
  • Africa/Freetown
  • Africa/Lome
  • Africa/Monrovia
  • Africa/Nouakchott
  • Africa/Ouagadougou
  • Africa/Sao_Tome
  • Africa/Timbuktu
  • America/Danmarkshavn
  • Atlantic/Reykjavik
  • Atlantic/St_Helena
  • Eire
  • Etc/GMT
  • Etc/GMT+0
  • Etc/GMT-0
  • Etc/GMT0
  • Etc/Greenwich
  • Europe/Belfast
  • Europe/Dublin
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire
  • GMT
  • GMT+0
  • GMT-0
  • GMT0
  • Greenwich
  • Iceland
Time zones with the GMT +0 offset:
  • EGST - Eastern Greenland Summer Time
  • GMT - Greenwich Mean Time
  • WET - Western European Time
  • AZOST - Azores Summer Time
  • UTC - Universal Time Coordinated
  • WT - Western Sahara Standard Time
  • Z - Zulu Time Zone