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CST Caribbean to AST Converter

Updating current time…
CST
Cuba Standard Time
GMT -5
12am
3am
6am
9am
12pm
3pm
6pm
9pm
AST
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

For most of the year, CDT Caribbean is 1 hour behind ADT. During seasonal clock changes, CST Caribbean is 1 hour behind AST. Briefly around those changes, CDT Caribbean and AST have the same time.

For most of the year, working hours of 9:00 am to 5:00 pm in CDT Caribbean correspond to 10:00 am to 6:00 pm in ADT. During seasonal clock changes, working hours of 9:00 am to 5:00 pm in CST Caribbean correspond to 10:00 am to 6:00 pm in AST.

For example, 7:00 am CST is 8:00 am AST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 9am-4pm CST, which is 10am-5pm AST.

Compare CST time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Cuba Standard Time is 1 hour behind Atlantic Standard Time
7:00 am07:00 in CST is 8:00 am08:00 in AST

CST to AST call time
Best time for a conference call or a meeting is between 9am-4pm in CST which corresponds to 10am-5pm in AST

7:00 am07:00 Cuba Standard Time (CST). Offset UTC -5:00 hours
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

7:00 am07:00 CST / 8:00 am08:00 AST

CSTAST
12am (midnight)1am
1am2am
2am3am
3am4am
4am5am
5am6am
6am7am
7am8am
8am9am
9am10am
10am11am
11am12pm (noon)
12pm (noon)1pm
1pm2pm
2pm3pm
3pm4pm
4pm5pm
5pm6pm
6pm7pm
7pm8pm
8pm9pm
9pm10pm
10pm11pm
11pm12am (midnight)
00:0001:00
01:0002:00
02:0003:00
03:0004:00
04:0005:00
05:0006:00
06:0007:00
07:0008:00
08:0009:00
09:0010:00
10:0011:00
11:0012:00
12:0013:00
13:0014:00
14:0015:00
15:0016:00
16:0017:00
17:0018:00
18:0019:00
19:0020:00
20:0021:00
21:0022:00
22:0023:00
23:0000:00

Cuba Standard Time

Offset: CST is 5 hours behind Greenwich Mean Time (GMT) and is used in Caribbean

Countries using this time zone: Cuba

Principal Cities: The largest city in the CST time zone is Havana in Cuba, with about 2.164 million people. Other major cities in this time zone include Santiago de Cuba, Camaguey, Holguin, Guantanamo.

CST Time Zone Geo Map
CST timezone map

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Cuba Daylight Time (CDT).

Daylight saving time clock moves back for one hour from 1am to 12amStart: Cuba Standard Time (CST) started on Sunday, November 2, 2025 at 1:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 12:00 am. Standard time starts annually on the first Sunday of November.

Daylight saving time clock moves forward for one hour from 12am to 1amEnd: Cuba Standard Time (CST) ends on Sunday, March 8, 2026 at 12:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 1:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.

CST 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 an offset of five hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Romeo - Military abbreviation for CST
  • R - short form of 'Romeo'
IANA/Olson: Reflects CST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Havana
  • Cuba
CST Abbreviation: Several time zones share CST abbreviation and it could refer to these time zones
  • Central Standard Time - UTC -6
  • China Standard Time - UTC +8
  • Cuba Standard Time - UTC -5
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

Atlantic Standard Time

Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)

Principal Cities: The largest city in the AST time zone is Santo Domingo in Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax.

French: HNA - Heure Normale de l'Atlantique

Spanish: AST - Tiempo Estándar del Atlántico

AST Time Zone Geo Map
AST timezone map

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).

Daylight saving time clock moves back for one hour from 2am to 1amStart: Atlantic Standard Time (AST) started on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the first Sunday of November.

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Atlantic Standard Time (AST) ends on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.

AST 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 an offset of four hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Quebec - Military abbreviation for AST
  • Q - short form of 'Quebec'
IANA/Olson: Reflects AST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Anguilla
  • America/Antigua
  • America/Aruba
  • America/Barbados
  • America/Blanc-Sablon
  • America/Curacao
  • America/Dominica
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Grenada
  • America/Guadeloupe
  • America/Halifax
  • America/Kralendijk
  • America/Lower_Princes
  • America/Marigot
  • America/Martinique
  • America/Moncton
  • America/Montserrat
  • America/Port_of_Spain
  • America/Puerto_Rico
  • America/Santo_Domingo
  • America/St_Barthelemy
  • America/St_Kitts
  • America/St_Lucia
  • America/St_Thomas
  • America/St_Vincent
  • America/Thule
  • America/Tortola
  • America/Virgin
  • Atlantic/Bermuda
  • Canada/Atlantic
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
  • Atlantic Standard Time - UTC -4
  • Arabia Standard Time - UTC +3
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
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT