HST/HDT
Hawaii Standard Time
GMT -10
HDT automatically adjusted to HST time zone, that is in use
HST
Hawaii Standard Time
GMT -10

Time Difference

Hawaii Standard Time is 0 hours ahead of Hawaii Standard Time
So 4:30 am04:30 in HST is 4:30 am04:30 in HST

4:30 am04:30 Hawaii Standard Time (HST). Offset UTC -10:00 hours
4:30 am04:30 Hawaii Standard Time (HST). Offset UTC -10:00 hours

4:30 am04:30 HST / 4:30 am04:30 HST

HST HST
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
0:00 0:00
1:00 1:00
2:00 2:00
3:00 3:00
4:00 4:00
5:00 5:00
6:00 6:00
7:00 7:00
8:00 8:00
9:00 9:00
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 Daylight Time

Offset: HDT is 9 hours behind Greenwich Mean Time (GMT) and is used in Pacific

Countries: It is used in following countries: United States

Daylight Saving: Hawaii Daylight Time (HDT) is a daylight saving/summer timezone, however during winter some places switch clocks for one hour back and observe Hawaii Standard Time (HST).

Start: Hawaii Daylight Time (HDT) started and clocks were set one hour forward on Sunday, 08 March 2020, at 2:00 (2:00 am) local time.

End: Hawaii Daylight Time (HDT) ends and clocks are set one hour back on Sunday, 01 November 2020, at 2:00 (2:00 am) local time.

HDT 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 nine 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
  • Victor - Military abbreviation for HDT
  • V - short form of 'Victor'

IANA/Olson: Reflects HDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Adak
  • America/Atka
  • US/Aleutian

Time zones with the GMT -9 offset:

  • AKST - Alaska Standard Time
  • AHDT - Alaska-Hawaii Daylight Time
  • HADT - Hawaii-Aleutian Daylight Time
  • YST - Yukon Standard Time
  • GAMT - Gambier Time
  • HDT - Hawaii Daylight Time
  • V - Victor Time Zone
  • -09 -


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 371,657 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 adjust time for one hour forward for daylight saving and observe Hawaii Daylight Time (HDT).

End: HST ended and clocks were set one hour forward on Sunday, 08 March 2020, at 2:00 (2:00 am) local time.

Start: HST starts and clocks are set one hour back on Sunday, 01 November 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
  • GMT - GMT-10:00