GMT/BST
Greenwich Mean Time
GMT +0
BST automatically adjusted to GMT time zone, that is in use
CST/CDT
Central Standard Time
GMT -6
CDT automatically adjusted to CST time zone, that is in use

Time Difference

Greenwich Mean Time is 6 hours ahead of Central Standard Time
9:30 am09:30 in GMT is 3:30 am03:30 in CST

BST to CDT call time
Best time for a conference call or a meeting is between 2pm-6pm in BST which corresponds to 8am-12pm in CDT

9:30 am09:30 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
3:30 am03:30 Central Standard Time (CST). Offset UTC -6:00 hours

9:30 am09:30 GMT / 3:30 am03:30 CST

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

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 - Mitteleuropäische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time

Central Daylight Time

Offset: CDT is 5 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries: It is used in following countries: Canada, Cuba, Mexico, United States

Principal Cities: The largest city in the CDT timezone is Chicago from USA with population about 2.696 million people. Other major cities in the area are Havana, Houston, Ciudad Juarez, San Antonio

French: HAC - Heure Avancée du Centre

Spanish: CT - Zona Centro

CDT Time Zone Geo Map
CDT timezone map

Daylight Saving: Central Daylight Time (CDT) is a daylight saving/summer time zone, however during winter some places adjust time for one hour back and observe Central Standard Time (CST).

Daylight saving time clock moves back for one hour from 2am to 1amEnd: Central Daylight Time (CDT) has ended on Sunday, November 3, 2024 at 2:00 am local time and clocks were set one hour back to Sunday, November 3, 2024, 1:00 am local standard time instead. Daylight saving ends annually the on first Sunday of November

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Central Daylight Time (CDT) starts on Sunday, March 9, 2025 at 2:00 am local time and clocks are set one hour forward to Sunday, March 9, 2025, 3:00 am. Daylight saving starts annually the on second Sunday of March

CDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -05 - basic short
  • -0500 - basic
  • -05:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0500 - sign character (-) followed by a four digit time providing hours (05) and minutes (00) of the offset. Indicates five 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
  • Romeo - Military abbreviation for CDT
  • R - short form of 'Romeo'
IANA/Olson: Reflects CDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Chicago
  • America/Indiana/Knox
  • America/Indiana/Tell_City
  • America/Knox_IN
  • America/Matamoros
  • America/Menominee
  • America/North_Dakota/Beulah
  • America/North_Dakota/Center
  • America/North_Dakota/New_Salem
  • America/Ojinaga
  • America/Rainy_River
  • America/Rankin_Inlet
  • America/Resolute
  • America/Winnipeg
  • CST6CDT
  • Canada/Central
  • US/Central
  • US/Indiana-Starke
CDT Abbreviation: Several time zones share CDT abbreviation and it could refer to these time zones
  • Central Daylight Time - UTC -5
  • Cuba Daylight Time - UTC -4
Time zones with the GMT -5 offset:
  • CDT - Central Daylight Time
  • EST - Eastern Standard Time
  • ET - Eastern Time
  • COT - Colombia Time
  • CST - Cuba Standard Time
  • EASST - Easter Island Summer Time
  • ECT - Ecuador Time
  • PET - Peru Time
  • R - Romeo Time Zone