HST to UTC Converter
No shared working hoursThu, Oct 15
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
2:00 am02:00 HST (UTC-10), Oct 15, 2026 = 12:00 pm12:00 UTC (UTC+0), Oct 15, 2026
HST is 10 hours behind UTC.
HST and UTC examples
These examples always use HST (UTC-10) and UTC (UTC+0). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
HST is 10 hours behind UTC.
How the time difference changes
HST is 10 hours behind UTC year-round.
Working hours of 9:00 am to 6:00 pm in HST correspond to 7:00 pm to 4:00 am (next day) in UTC.Working hours of 09:00 to 18:00 in HST correspond to 19:00 to 04:00 (next day) in UTC.
Compare HST time with UTC time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Hawaii Standard Time is 10 hours behind Coordinated Universal Time.
2:00 am02:00 in HST is 12:00 pm12:00 in UTC
HST to UTC call time
Best time for a conference call or a meeting is between 8am-9am08:00-09:00 in HST which corresponds to 6pm-7pm18:00-19:00 in UTC. Their 9am–6pm09:00–18:00 working hours do not overlap; this is a suggested compromise.
2:00 am02:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours
12:00 pm12:00 Coordinated Universal Time (UTC). Offset UTC 0:00 hours
2:00 am02:00 HST / 12:00 pm12:00 UTC
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.
| HST | UTC |
|---|---|
| 10:00am | |
| 11:00am | |
| 12:00pm | |
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Hawaii Standard Time
Offset: HST is 10 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: United States
Principal Cities: The largest city in the HST time zone is Honolulu in the United States, with about 350,964 people. Other major cities in this time zone include Pearl City, Hilo, Kailua, Waipahu.
Daylight Saving: Some places on Hawaii Standard Time (HST) keep the same time all year, while others use HST for only part of the year and change their clocks for daylight saving time; see upcoming clock changes worldwide.
Today the lighter areas are on UTC−9 (HDT).
HST 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 HST
- W - short form of 'Whiskey'
- America/Adak
- America/Atka
- HST
- Pacific/Honolulu
- Pacific/Johnston
- US/Aleutian
- US/Hawaii
- HAST - Hawaii-Aleutian Standard Time
- CKT - Cook Island Time
- HST - Hawaii Standard Time
- TAHT - Tahiti Time
- W - Whiskey Time Zone
Coordinated Universal Time
Offset: UTC is the same as Greenwich Mean Time (GMT).
Coordinated Universal Time (UTC) is the world time standard that regulates clocks and time. It is the successor to Greenwich Mean Time (GMT). For casual use, UTC is the same as GMT, but UTC is the standard the scientific community uses.
UTC has been the time standard commonly used across the world since 1972. It is used in many technical fields, such as aviation and meteorology, and to synchronize time across internet networks.
Today some of the lighter areas are on UTC+1 (British Summer Time, Irish Standard Time, WEST).
UTC 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 UTC
- Z - short form of 'Zulu'
- Etc/UCT
- Etc/UTC
- Etc/Universal
- Etc/Zulu
- UCT
- UTC
- Universal
- Zulu
- 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