CDT
Central Daylight Time
GMT -5
GMT/BST
Greenwich Mean Time
GMT +0
BST automatically adjusted to GMT time zone, that is in use

Time Difference

Central Daylight Time is 5 hours behind Greenwich Mean Time
6:00 am06:00 in CDT is 11:00 am11:00 in GMT

CDT to GMT call time
Best time for a conference call or a meeting is between 9am-12pm in CDT which corresponds to 2pm-5pm in GMT

6:00 am06:00 Central Daylight Time (CDT). Offset UTC -5:00 hours
11:00 am11:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours

6:00 am06:00 CDT / 11:00 am11:00 GMT

CDT GMT
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 12am (midnight)
8pm 1am
9pm 2am
10pm 3am
11pm 4am
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 0:00
20:00 1:00
21:00 2:00
22:00 3:00
23:00 4:00

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, 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 Houston, Ciudad Juarez, San Antonio, Dallas

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 timezone, however during winter some places switch clocks for one hour back and observe Central Standard Time (CST).

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Central Daylight Time (CDT) started on Sunday, March 8, 2026 at 2:00 am local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am. Daylight saving starts annually the on second Sunday of March

Daylight saving time clock moves back for one hour from 2am to 1amEnd: Central Daylight Time (CDT) ends on Sunday, November 1, 2026 at 2:00 am local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am local standard time instead. Daylight saving ends annually the on first Sunday of November

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

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