GMT/BST
Greenwich Mean Time
GMT +0
BST automatically adjusted to GMT time zone, that is in use
IRST
Iran Standard Time
GMT +3:30

Time Difference

Greenwich Mean Time is 3 hours and 30 minutes behind of Iran Standard Time
1:00 am01:00 in GMT is 4:30 am04:30 in IRST

BST to IRST call time
Best time for a conference call or a meeting is between 8am-3:30pm in BST which corresponds to 10:30am-6pm in IRST

1:00 am01:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
4:30 am04:30 Iran Standard Time (IRST). Offset UTC +3:30 hours

1:00 am01:00 GMT / 4:30 am04:30 IRST

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

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

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 -