GMT
Greenwich Mean Time
GMT +0
CDT
Cuba Daylight Time
GMT -4

Time Difference

Greenwich Mean Time is 4 hours ahead of Cuba Daylight Time
8:30 pm20:30 in GMT is 4:30 pm16:30 in CDT

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

8:30 pm20:30 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
4:30 pm16:30 Cuba Daylight Time (CDT). Offset UTC -4:00 hours

8:30 pm20:30 GMT / 4:30 pm16:30 CDT

GMT CDT
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

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
GMT Abbreviation: Several time zones share GMT abbreviation and it could refer to these time zones
  • Greenwich Mean Time - UTC +0
  • GMT+03:00 - UTC +3
  • GMT - UTC +1
  • GMT+06:00 - UTC +6
  • GMT-01:00 - UTC -1
  • GMT+11:00 - UTC +11
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

Cuba Daylight Time

Offset: CDT is 4 hours behind Greenwich Mean Time (GMT) and is used in Caribbean

Countries: It is used in following countries: Cuba

Principal Cities: The largest city in the CDT timezone is Havana from Cuba with population about 2.164 million people. Other major cities in the area are Santiago de Cuba, Camaguey, Holguin, Guantanamo

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

Daylight saving time clock moves forward for one hour from 12am to 1amStart: Cuba Daylight Time (CDT) started on Sunday, March 10, 2024 at 12:00 am local time and clocks were set one hour forward to Sunday, March 10, 2024, 1:00 am. Daylight saving starts annually the on second Sunday of March

Daylight saving time clock moves back for one hour from 1am to 12amEnd: Cuba Daylight Time (CDT) ends on Sunday, November 3, 2024 at 1:00 am local time and clocks are set one hour back to Sunday, November 3, 2024, 12:00 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
  • -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 CDT
  • Q - short form of 'Quebec'
IANA/Olson: Reflects CDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Havana
  • Cuba
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 -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