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.
HST
Hawaii Standard Time
GMT -10
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Compare HADT time with HST 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 0 hours ahead of Hawaii Standard Time
2:00 am02:00 in HAST is 2:00 am02:00 in HST

HAST to HST call time
Best time for a conference call or a meeting is between 9am-5pm in HAST which corresponds to 9am-5pm in HST

2:00 am02:00 Hawaii-Aleutian Standard Time (HAST). Offset UTC -10:00 hours
2:00 am02:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours

2:00 am02:00 HAST / 2:00 am02:00 HST

HASTHST
12am (midnight)12am (midnight)
1am1am
2am2am
3am3am
4am4am
5am5am
6am6am
7am7am
8am8am
9am9am
10am10am
11am11am
12pm (noon)12pm (noon)
1pm1pm
2pm2pm
3pm3pm
4pm4pm
5pm5pm
6pm6pm
7pm7pm
8pm8pm
9pm9pm
10pm10pm
11pm11pm
00:0000:00
01:0001:00
02:0002:00
03:0003:00
04:0004:00
05:0005:00
06:0006:00
07:0007:00
08:0008:00
09:0009:00
10:0010:00
11:0011:00
12:0012:00
13:0013:00
14:0014:00
15:0015:00
16:0016:00
17:0017:00
18:0018:00
19:0019:00
20:0020:00
21:0021:00
22:0022:00
23:0023:00

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

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 Time Zone Geo Map
HST timezone map

HST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -10 - basic short
  • -1000 - basic
  • -10:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -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.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Whiskey - Military abbreviation for HST
  • W - short form of 'Whiskey'
IANA/Olson: Reflects HST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Adak
  • America/Atka
  • HST
  • Pacific/Honolulu
  • Pacific/Johnston
  • US/Aleutian
  • US/Hawaii
Time zones with the GMT -10 offset:
  • HAST - Hawaii-Aleutian Standard Time
  • CKT - Cook Island Time
  • HST - Hawaii Standard Time
  • TAHT - Tahiti Time
  • W - Whiskey Time Zone