HDT to GMT Converter
HDT is not used on this date
This converter keeps HDT at UTC−9. Honolulu uses HST (UTC−10) on this date. Open the HST converter, or choose Honolulu, Pearl City, or Hilo for city-specific time.The United Kingdom is on summer time: BST (UTC+1) until Sun, Oct 25.
Iceland and Ghana stay on GMT (UTC+0).
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
3:00 am03:00 HDT (UTC-9), Oct 18, 2026 = 12:00 pm12:00 GMT (UTC+0), Oct 18, 2026
HDT is 9 hours behind GMT.
HDT and GMT examples
These examples always use HDT (UTC-9) 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.
HDT is 9 hours behind GMT.
How the time difference changes
HDT is 9 hours behind GMT year-round.
Working hours of 9:00 am to 6:00 pm in HDT correspond to 6:00 pm to 3:00 am (next day) in GMT.Working hours of 09:00 to 18:00 in HDT correspond to 18:00 to 03:00 (next day) in GMT.
Compare HDT time with GMT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Hawaii Daylight Time is 9 hours behind Greenwich Mean Time.
3:00 am03:00 in HDT is 12:00 pm12:00 in GMT
HDT to GMT call time
Best time for a conference call or a meeting is between 8:30am-9:30am08:30-09:30 in HDT which corresponds to 5:30pm-6:30pm17:30-18:30 in GMT. Their 9am–6pm09:00–18:00 working hours do not overlap; this is a suggested compromise.
3:00 am03:00 Hawaii Daylight Time (HDT). Offset UTC -9:00 hours
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
3:00 am03:00 HDT / 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.
| HDT | GMT |
|---|---|
| 9:00am | |
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| 09:00 | |
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Hawaii Daylight Time
Offset: HDT is 9 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: United States
Today all shaded areas are on HDT.
HDT representations, usage and related time zones
- -09 - basic short
- -0900 - basic
- -09:00 - extended
- -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.
- Victor - Military abbreviation for HDT
- V - short form of 'Victor'
- America/Adak
- America/Atka
- US/Aleutian
- 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 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