HST/HDT
Hawaii Standard Time
GMT -10
HDT automatically adjusted to HST time zone, that is in use
BST
British Summer Time
GMT +1

Time Difference

Hawaii Standard Time is 11 hours behind of British Summer Time
So 9:30 pm21:30 in HST is 8:30 am08:30 in BST

9:30 pm21:30 Hawaii Standard Time (HST). Offset UTC -10:00 hours
8:30 am08:30 British Summer Time (BST). Offset UTC +1:00 hour

9:30 pm21:30 HST / 8:30 am08:30 BST

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

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 -


British Summer Time

Offset: BST is 1 hour ahead Greenwich Mean Time (GMT) and is used in Europe

Countries: It is used in following countries: Britain (UK), Guernsey, Isle of Man, Jersey

Principal Cities: The largest city in the BST timezone is London from United Kingdom with population about 7.557 million people. Other major cities in the area are Birmingham, Glasgow, Liverpool, Saint Helier

Daylight Saving: British Summer Time (BST) is a daylight saving/summer timezone, however during winter some places switch clocks for one hour back and observe Greenwich Mean Time (GMT).

Start: British Summer Time (BST) started and clocks were set one hour forward on Sunday, 29 March 2020, at 1:00 (1:00 am) local time.

End: British Summer Time (BST) ends and clocks are set one hour back on Sunday, 25 October 2020, at 2:00 (2:00 am) local time.

BST Time Zone Geo Map
BST timezone map
BST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +01 - basic short
  • +0100 - basic
  • +01:00 - extended

Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0100 - sign character (+) followed by a four digit time providing hours (01) and minutes (00) of the offset. Indicates one hour and zero minutes time differences to the east of the zero meridian.

Military/NATO: Used by the U.S. military, Chinese military and others
  • Alpha - Military abbreviation for BST
  • A - short form of 'Alpha'

IANA/Olson: Reflects BST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Europe/Belfast
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire

BST Abbreviation: Several time zones share BST abbreviation and it could refer to these time zones

  • British Summer Time - UTC +1
  • Bangladesh Standard Time - UTC +6
  • Bougainville Standard Time - UTC +11

Time zones with the GMT +1 offset:

  • BST - British Summer Time
  • CET - Central European Time
  • IST - Irish Standard Time
  • WEST - Western European Summer Time
  • A - Alpha Time Zone
  • CET - Central European Time
  • MEZ - Mitteleurop√ɬ§ische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time
  • GMT - GMT
  • +01 -