HST to HAST Converter
Quick answers
Selected conversion
The selected date and time will appear here when the converter loads.
HST and HAST examples
These examples always use HST (UTC-10) and HAST (UTC-10). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
HST and HAST have the same local time.
How the time difference changes
HST and HAST have the same time year-round.
Working hours of 9:00 am to 5:00 pm in HST correspond to 9:00 am to 5:00 pm in HAST.
Compare HST time with HAST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Hawaii Standard Time is 0 hours ahead of Hawaii-Aleutian Standard Time
2:00 am02:00 in HST is 2:00 am02:00 in HAST
HST to HAST call time
Best time for a conference call or a meeting is between 9am-5pm in HST which corresponds to 9am-5pm in HAST
2:00 am02:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours
2:00 am02:00 Hawaii-Aleutian Standard Time (HAST). Offset UTC -10:00 hours
2:00 am02:00 HST / 2:00 am02:00 HAST
| HST | HAST |
|---|---|
| 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 |
| 00:00 | 00:00 |
| 01:00 | 01:00 |
| 02:00 | 02:00 |
| 03:00 | 03:00 |
| 04:00 | 04:00 |
| 05:00 | 05:00 |
| 06:00 | 06:00 |
| 07:00 | 07:00 |
| 08:00 | 08:00 |
| 09:00 | 09:00 |
| 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 |
Hawaii Standard Time
Offset: HST is 10 hours behind Greenwich Mean Time (GMT) and is used in Pacific
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 371,657 people. Other major cities in this time zone include Pearl City, Hilo, Kailua, Waipahu.
Daylight Saving: Clocks in Hawaii Standard Time (HST) do not change for daylight saving time, so HST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

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
Hawaii-Aleutian Standard Time
Offset: HAST is 10 hours behind Greenwich Mean Time (GMT) and is used in America
Countries using this time zone: United States
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).
Start: Hawaii-Aleutian Standard Time (HAST) started 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. Standard time starts annually on the first Sunday of November.
End: Hawaii-Aleutian Standard Time (HAST) ends 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 local daylight time instead. Standard time ends annually on the second Sunday of March.
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
