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

Time Difference

Central Standard Time is 6 hours behind of Greenwich Mean Time
So 6:30 pm18:30 in CST is 12:30 am00:30 in GMT

6:30 pm18:30 Central Standard Time (CST). Offset UTC -6:00 hours
12:30 am00:30 Greenwich Mean Time (GMT). Offset UTC 0:00 hours

6:30 pm18:30 CST / 12:30 am00:30 GMT

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

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 Mexico City from Mexico with population about 12.294 million people. Other major cities in the area are Chicago, Havana, Houston, Iztapalapa

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

End: CDT ends annually on the same date and time. and clocks were set one hour back on Sunday, November 3, 2019, at 2:00 (2:00 am) local time.

Start: CDT starts annually on the same date and time. and clocks are set one hour forward on Sunday, March 8, 2020, at 2:00 (2:00 am) local time.

French: HAC - Heure Avancée du Centre

Spanish: CT - Zona Centro

CDT Time Zone Geo Map
CDT timezone map
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/Bahia_Banderas
  • America/Chicago
  • America/Indiana/Knox
  • America/Indiana/Tell_City
  • America/Knox_IN
  • America/Matamoros
  • America/Menominee
  • America/Merida
  • America/Mexico_City
  • America/Monterrey
  • America/North_Dakota/Beulah
  • America/North_Dakota/Center
  • America/North_Dakota/New_Salem
  • America/Rainy_River
  • America/Rankin_Inlet
  • America/Resolute
  • America/Winnipeg
  • CST6CDT
  • Canada/Central
  • Mexico/General
  • 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
  • -05 -
  • CWT -


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 - Mitteleuropäische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time
  • +01 -