HAST to GMT Converter
HAST is not used on this date
This converter keeps HAST at UTC−10. Adak uses HDT (UTC−9) on this date. Open the HDT converter.The United Kingdom is on summer time: BST (UTC+1) until Sun, Oct 25.
Iceland and Ghana stay on GMT (UTC+0).
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Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
2:00 am02:00 HAST (UTC-10), Oct 17, 2026 = 12:00 pm12:00 GMT (UTC+0), Oct 17, 2026
HAST is 10 hours behind GMT.
HAST and GMT examples
These examples always use HAST (UTC-10) and GMT (UTC+0). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
HAST is 10 hours behind GMT.
How the time difference changes
HAST is 10 hours behind GMT year-round.
Working hours of 9:00 am to 6:00 pm in HAST correspond to 7:00 pm to 4:00 am (next day) in GMT.Working hours of 09:00 to 18:00 in HAST correspond to 19:00 to 04:00 (next day) in GMT.
Compare HAST 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 8am-9am08:00-09:00 in HAST which corresponds to 6pm-7pm18:00-19:00 in GMT. Their 9am–6pm09:00–18:00 working hours do not overlap; this is a suggested compromise.
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
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
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Hawaii-Aleutian Standard Time
Offset: HAST is 10 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: United States
Today the shaded areas are on UTC−9 (HDT).
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Hawaii-Aleutian Daylight Time (HADT).
End: Hawaii-Aleutian Standard Time (HAST) ended on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00 local daylight time instead. Standard time ends annually on the second Sunday of March.
Start: Hawaii-Aleutian Standard Time (HAST) starts on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00. Standard time starts annually on the first Sunday of November.
See USA daylight saving time and upcoming clock changes worldwide.
HAST representations, usage and related time zones
- -10 - basic short
- -1000 - basic
- -10:00 - extended
- -1000 - sign character (-) followed by a four digit time providing hours (10) and minutes (00) of the offset. Indicates an offset of ten hours to the west of the zero meridian.
- Whiskey - Military abbreviation for HAST
- W - short form of 'Whiskey'
- HAST - Hawaii-Aleutian Standard Time
- CKT - Cook Island Time
- HST - Hawaii Standard Time
- TAHT - Tahiti Time
- W - Whiskey Time Zone
Greenwich Mean Time
Offset: GMT is the same as Greenwich Mean Time (GMT).
Countries using this time zone: Antarctica, Burkina Faso, Gambia, Ghana, Greenland, Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Morocco, Saint Helena, São Tomé and Príncipe, Senegal, Sierra Leone, Togo, United Kingdom, Western Sahara
Principal Cities: The largest city in the GMT time zone is London in the United Kingdom, with about 8.962 million people. Other major cities in this time zone include Abidjan, Bamako, Casablanca, Dakar.
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 the two are the same. In the military, GMT is known as Zulu time. Greenwich Mean Time was the same as Universal Time (UT), a standard astronomical concept used in many technical fields, until the introduction of UTC in 1972.
Today the lighter areas are on UTC+1 (British Summer Time, Irish Standard Time).
GMT representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for GMT
- Z - short form of 'Zulu'
- 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
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Coordinated Universal Time
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone