GMT/BST
Greenwich Mean Time
GMT +0
BST automatically adjusted to GMT time zone, that is in use
ACST
Australian Central Standard Time
GMT +9:30
ACST is NOT in use by many locations
ACDT (Australian Central Daylight Time) is used instead. Switch to ACDT time zone or select one of the cities Adelaide, Darwin, Adelaide Hills) for automatic timezone change.

Time Difference

Greenwich Mean Time is 9 hours and 30 minutes behind Australian Central Standard Time
10:30 pm22:30 in GMT is 8:00 am08:00 in ACST

BST to ACST call time
Best time for a conference call or a meeting is between 8am-10am in BST which corresponds to 4:30pm-6:30pm in ACST

10:30 pm22:30 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
8:00 am08:00 Australian Central Standard Time (ACST). Offset UTC +9:30 hours

10:30 pm22:30 GMT / 8:00 am08:00 ACST

GMT ACST
12am (midnight) 9:30 am
1am 10:30 am
2am 11:30 am
3am 12:30 pm
4am 1:30 pm
5am 2:30 pm
6am 3:30 pm
7am 4:30 pm
8am 5:30 pm
9am 6:30 pm
10am 7:30 pm
11am 8:30 pm
12pm (noon) 9:30 pm
1pm 10:30 pm
2pm 11:30 pm
3pm 12:30 am
4pm 1:30 am
5pm 2:30 am
6pm 3:30 am
7pm 4:30 am
8pm 5:30 am
9pm 6:30 am
10pm 7:30 am
11pm 8:30 am
0:00 9:30
1:00 10:30
2:00 11:30
3:00 12:30
4:00 13:30
5:00 14:30
6:00 15:30
7:00 16:30
8:00 17:30
9:00 18:30
10:00 19:30
11:00 20:30
12:00 21:30
13:00 22:30
14:00 23:30
15:00 0:30
16:00 1:30
17:00 2:30
18:00 3:30
19:00 4:30
20:00 5:30
21:00 6:30
22:00 7:30
23:00 8:30

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

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.

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
  • Brasilia Standard Time - UTC -3
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

Australian Central Standard Time

Offset: ACST is 9 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Australia

Countries: It is used in following countries: Australia

Principal Cities: The largest city in the ACST timezone is Adelaide from Australia with population about 1.225 million people. Other major cities in the area are Darwin, Adelaide Hills, Alice Springs, Palmerston

ACST Time Zone Geo Map
ACST timezone map

Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Australian Central Daylight Time (ACDT).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Australian Central Standard Time (ACST) has ended on Sunday, October 2, 2022 at 2:00 am local time and clocks were set one hour forward to Sunday, October 2, 2022, 3:00 am local daylight time instead. Standard time ends annually the on first Sunday of October.

Daylight saving time clock moves back for one hour from 3am to 2amStart: Australian Central Standard Time (ACST) starts on Sunday, April 2, 2023 at 3:00 am local time and clocks are set one hour back to Sunday, April 2, 2023, 2:00 am. Standard time starts annually the on first Sunday of April.

ACST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0930 - basic
  • +09:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0930 - sign character (+) followed by a four digit time providing hours (09) and minutes (30) of the offset. Indicates nine hour and thirty minutes time differences to the east of the zero meridian.
IANA/Olson: Reflects ACST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Australia/Adelaide
  • Australia/Broken_Hill
  • Australia/Darwin
  • Australia/North
  • Australia/South
  • Australia/Yancowinna