GMT/BST
Greenwich Mean Time
GMT +0
BST automatically adjusted to GMT time zone, that is in use
-04
GMT -4
-04 is NOT in use by many locations
-03 () is used instead. Switch to -03 time zone or select one of the cities Santiago, Caracas, Maracaibo) for automatic timezone change.

Time Difference

Greenwich Mean Time is 4 hours ahead of
12:00 am00:00 in GMT is 8:00 pm20:00 in -04

BST to -04 call time
Best time for a conference call or a meeting is between 1pm-6pm in BST which corresponds to 8am-1pm in -04

12:00 am00:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
8:00 pm20:00 (-04). Offset UTC -4:00 hours

12:00 am00:00 GMT / 8:00 pm20:00 -04

GMT -04
12am (midnight) 8pm
1am 9pm
2am 10pm
3am 11pm
4am 12am (midnight)
5am 1am
6am 2am
7am 3am
8am 4am
9am 5am
10am 6am
11am 7am
12pm (noon) 8am
1pm 9am
2pm 10am
3pm 11am
4pm 12pm (noon)
5pm 1pm
6pm 2pm
7pm 3pm
8pm 4pm
9pm 5pm
10pm 6pm
11pm 7pm
0:00 20:00
1:00 21:00
2:00 22:00
3:00 23:00
4:00 0:00
5:00 1:00
6:00 2:00
7:00 3:00
8:00 4:00
9:00 5:00
10:00 6:00
11:00 7:00
12:00 8:00
13:00 9:00
14:00 10:00
15:00 11:00
16:00 12:00
17:00 13:00
18:00 14:00
19:00 15:00
20:00 16:00
21:00 17:00
22:00 18:00
23:00 19:00

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

-04

Offset: -04 is 4 hours behind Greenwich Mean Time (GMT) and is used in America

Countries: It is used in following countries: Bolivia, Brazil, Chile, Guyana, Paraguay, Venezuela

Principal Cities: The largest city in the -04 timezone is Santiago from Chile with population about 4.837 million people. Other major cities in the area are Caracas, Maracaibo, Maracay, Manaus

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 (-03).

Daylight saving time clock moves forward for one hour from 12am to 1amEnd: (-04) has ended on Sunday, October 2, 2022 at 12:00 am local time and clocks were set one hour forward to Sunday, October 2, 2022, 1:00 am local daylight time instead. Standard time ends .

Daylight saving time clock moves back for one hour from 12am to 11pmStart: (-04) starts on Sunday, March 26, 2023 at 12:00 am local time and clocks are set one hour back to Saturday, March 25, 2023, 11:00 pm. Standard time starts .

-04 representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -04 - basic short
  • -0400 - basic
  • -04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates four 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
  • Quebec - Military abbreviation for -04
  • Q - short form of 'Quebec'
IANA/Olson: Reflects -04 time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Asuncion
  • America/Boa_Vista
  • America/Campo_Grande
  • America/Caracas
  • America/Cuiaba
  • America/Guyana
  • America/La_Paz
  • America/Manaus
  • America/Porto_Velho
  • America/Santiago
  • Brazil/West
  • Chile/Continental
  • Etc/GMT+4
Time zones with the GMT -4 offset:
  • AST - Atlantic Standard Time
  • EDT - Eastern Daylight Time
  • AMT - Amazon Time
  • BOT - Bolivia Time
  • CDT - Cuba Daylight Time
  • CLT - Chile Standard Time
  • FKT - Falkland Island Time
  • GYT - Guyana Time
  • HLV - Hora Legal de Venezuela
  • PYT - Paraguay Time
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time