HADT
Hawaii-Aleutian Daylight Time
GMT -9
HST
Hawaii Standard Time
GMT -10

Time Difference

Hawaii-Aleutian Daylight Time is 1 hour ahead of Hawaii Standard Time
So 12:00 pm12:00 in HADT is 11:00 am11:00 in HST

12:00 pm12:00 Hawaii-Aleutian Daylight Time (HADT). Offset UTC -9:00 hours
11:00 am11:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours

12:00 pm12:00 HADT / 11:00 am11:00 HST

HADT HST
12am (midnight) 11pm
1am 12am (midnight)
2am 1am
3am 2am
4am 3am
5am 4am
6am 5am
7am 6am
8am 7am
9am 8am
10am 9am
11am 10am
12pm (noon) 11am
1pm 12pm (noon)
2pm 1pm
3pm 2pm
4pm 3pm
5pm 4pm
6pm 5pm
7pm 6pm
8pm 7pm
9pm 8pm
10pm 9pm
11pm 10pm
0:00 23:00
1:00 0:00
2:00 1:00
3:00 2:00
4:00 3:00
5:00 4:00
6:00 5:00
7:00 6:00
8:00 7:00
9:00 8:00
10:00 9:00
11:00 10:00
12:00 11:00
13:00 12:00
14:00 13:00
15:00 14:00
16:00 15:00
17:00 16:00
18:00 17:00
19:00 18:00
20:00 19:00
21:00 20:00
22:00 21:00
23:00 22:00

Hawaii Standard Time

Offset: HST is 10 hours behind Greenwich Mean Time (GMT) and is used in Pacific

Countries: It is used in following countries: United States

Principal Cities: The largest city in the HST timezone is Honolulu from USA with population about 371657 people. Other major cities in the area are Pearl City, Hilo, Kailua, Waipahu

Daylight Saving: This is a standard timezone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Hawaii Daylight Time (HDT).

Start: HST started and clocks were set one hour back on Sunday, November 3, 2019, at 2:00 (2:00 am) local time.

End: HST ends and clocks are set one hour forward on Sunday, March 8, 2020, at 2:00 (2:00 am) local time.

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 ten hour and zero minutes time differences 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