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
1:00 am01:00 in HADT is 12:00 am00:00 in HST

HADT to HST call time
Best time for a conference call or a meeting is between 9am-6pm in HADT which corresponds to 8am-5pm in HST

1:00 am01:00 Hawaii-Aleutian Daylight Time (HADT). Offset UTC -9:00 hours
12:00 am00:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours

1:00 am01:00 HADT / 12:00 am00:00 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-Aleutian Daylight Time

Offset: HADT is 9 hours behind Greenwich Mean Time (GMT) and is used in North America

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 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 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: 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: Hawaii Standard Time (HST) is not adjusted for daylight saving therefore HST remains the same through out the year. This means, unlike some time zones where the clock is set forward by one hour every summer and backward by one hour during winter to adjust for daylight saving, Hawaii Standard Time remains the same

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