GMT
Greenwich Mean Time
GMT +0
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
So 3:30 am03:30 in GMT is 9:30 pm21:30 in CST

3:30 am03:30 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
9:30 pm21:30 Central Standard Time (CST). Offset UTC -6:00 hours

3:30 am03:30 GMT / 9:30 pm21:30 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

Greenwich Mean Time

Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries: It is used in following countries: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo

Principal Cities: The largest city in the GMT timezone is London from United Kingdom with population about 7.557 million people. Other major cities in the area are Abidjan, Dakar, Grand Dakar, Accra

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.

GMT Time Zone Geo Map
GMT timezone map
GMT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
  • +00 - basic short
  • +0000 - basic
  • +00:00 - extended

Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates zero hour and zero minutes time differences of the zero meridian.

Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for GMT
  • Z - short form of 'Zulu'

IANA/Olson: Reflects GMT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Africa/Abidjan
  • Africa/Accra
  • Africa/Bamako
  • Africa/Banjul
  • Africa/Bissau
  • Africa/Conakry
  • Africa/Dakar
  • Africa/Freetown
  • Africa/Lome
  • Africa/Monrovia
  • Africa/Nouakchott
  • Africa/Ouagadougou
  • Africa/Sao_Tome
  • Africa/Timbuktu
  • America/Danmarkshavn
  • Atlantic/Reykjavik
  • Atlantic/St_Helena
  • Eire
  • Etc/GMT
  • Etc/GMT+0
  • Etc/GMT-0
  • Etc/GMT0
  • Etc/Greenwich
  • Europe/Belfast
  • Europe/Dublin
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire
  • GMT
  • GMT+0
  • GMT-0
  • GMT0
  • Greenwich
  • Iceland

Time zones with the GMT +0 offset:

  • EGST - Eastern Greenland Summer Time
  • GMT - Greenwich Mean Time
  • WET - Western European Time
  • AZOST - Azores Summer Time
  • UTC - Universal Time Coordinated
  • WT - Western Sahara Standard Time
  • Z - Zulu Time Zone
  • +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 -