CDT to AST Converter

Time Difference

Central Daylight Time is 1 hours behind of Atlantic Standard Time
So 5:21 AM05:21 in CDT is 6:21 AM06:21 in AST

5:21 AM05:21 Central Daylight Time (CDT). Offset UTC -5:00 hours
6:21 AM06:21 Atlantic Standard Time (AST). Offset UTC -4:00 hours

5:21 AM05:21 CDT / 6:21 AM06:21 AST

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 switch clocks for one hour back and observe Central Standard Time (CST).

Start: Central Daylight Time (CDT) starts annually on the same date and time. and clocks were set one hour forward on Sunday, March 10, 2019, at 2:00 (2:00 am) local time.

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

French: HAC - Heure Avancée du Centre

Spanish: CT - Zona Centro

CDT representations, usage and related time zones

• -05 - basic short
• -0500 - basic
• -05:00 - extended

• -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.

• Romeo - Military abbreviation for CDT
• R - short form of 'Romeo'

• 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 -5:00 h
• Cuba Daylight Time - UTC -4:00 h

Time zones with the GMT -5:00 h 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 -

Atlantic Standard Time

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

Countries: It is used in following countries: 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 timezone is Santo Domingo from Dominican Republic with population about 2.202 million people. Other major cities in the area are Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax

Daylight Saving: This is a standard timezone, however during summer some places adjust time for one hour forward for daylight saving and observe Atlantic Daylight Time (ADT).

End: AST ends annually on the same date and time. and clocks were set one hour forward on Sunday, March 10, 2019, at 2:00 (2:00 am) local time.

Start: AST starts annually on the same date and time. and clocks are set one hour back on Sunday, November 3, 2019, at 2:00 (2:00 am) local time.

French: HNA - Heure Normale de l'Atlantique

Spanish: AST - Tiempo Estándar del Atlántico

AST representations, usage and related time zones

• -04 - basic short
• -0400 - basic
• -04:00 - extended

• -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.

• Quebec - Military abbreviation for AST
• Q - short form of 'Quebec'

• 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 -4:00 h
• Arabia Standard Time - UTC +3:00 h

Time zones with the GMT -4:00 h 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
• PYT - Paraguay Time
• Q - Quebec Time Zone
• VET - Venezuelan Standard Time
• -04 -