CT to AST Converter
Time Difference
Central Daylight Time is 2 hours behind Atlantic Daylight Time
5:30 pm17:30 in CDT is 7:30 pm19:30 in ADT
CT to AST call time
Best time for a conference call or a meeting is between 8am-4pm in CT which corresponds to 10am-6pm in AST
5:30 pm17:30 Central Daylight Time (CDT). Offset UTC -5:00 hours
7:30 pm19:30 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
5:30 pm17:30 CDT / 7:30 pm19:30 ADT
CT | ADT |
---|---|
12am (midnight) | 2am |
1am | 3am |
2am | 4am |
3am | 5am |
4am | 6am |
5am | 7am |
6am | 8am |
7am | 9am |
8am | 10am |
9am | 11am |
10am | 12pm (noon) |
11am | 1pm |
12pm (noon) | 2pm |
1pm | 3pm |
2pm | 4pm |
3pm | 5pm |
4pm | 6pm |
5pm | 7pm |
6pm | 8pm |
7pm | 9pm |
8pm | 10pm |
9pm | 11pm |
10pm | 12am (midnight) |
11pm | 1am |
0:00 | 2:00 |
1:00 | 3:00 |
2:00 | 4:00 |
3:00 | 5:00 |
4:00 | 6:00 |
5:00 | 7:00 |
6:00 | 8:00 |
7:00 | 9:00 |
8:00 | 10:00 |
9:00 | 11:00 |
10:00 | 12:00 |
11:00 | 13:00 |
12:00 | 14:00 |
13:00 | 15:00 |
14:00 | 16:00 |
15:00 | 17:00 |
16:00 | 18:00 |
17:00 | 19:00 |
18:00 | 20:00 |
19:00 | 21:00 |
20:00 | 22:00 |
21:00 | 23:00 |
22:00 | 0:00 |
23:00 | 1:00 |
Central Time
Central Time (PT) is a general term used to describe the areas that observe either the Central Standard Time (CST) or Central Daylight Time (CDT) in the United States and Canada. CT is not static but switches between CDT and CST.
Territories observing the time zone are primarily in North and Central America. It runs through several Mexican and U.S. states, as well as several Canadian provinces and Central American countries.
Countries: It is used in following countries: Belize, Canada, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, El Salvador, United States.
Principal Cities: The largest city in the CST timezone is Mexico City from Mexico with population about 12.294 million people. Other major cities in the area are Chicago, Houston, Iztapalapa, Ecatepec.
French: HNC - Heure Normale du Centre
Spanish: CT - Tiempo Central Estándar, CT - Zona Centro
Central Time (PT) is a general term used to describe the areas that observe either the Central Standard Time (CST) or Central Daylight Time (CDT) in the United States and Canada. CT is not static but switches between CDT and CST.
Territories observing the time zone are primarily in North and Central America. It runs through several Mexican and U.S. states, as well as several Canadian provinces and Central American countries.
Countries: It is used in following countries: Belize, Canada, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, El Salvador, United States.
Principal Cities: The largest city in the CST timezone is Mexico City from Mexico with population about 12.294 million people. Other major cities in the area are Chicago, Houston, Iztapalapa, Ecatepec.
French: HNC - Heure Normale du Centre
Spanish: CT - Tiempo Central Estándar, CT - Zona Centro
CT representations, usage and related time zones
- -06 - basic short
- -0600 - basic
- -06:00 - extended
- -0600 - sign character (-) followed by a four digit time providing hours (06) and minutes (00) of the offset. Indicates six hour and zero minutes time differences to the west of the zero meridian.
- Sierra - Military abbreviation for CT
- S - short form of 'Sierra'
- Central Time - UTC -6
- Chuuk Time - UTC +10
- CST - Central Standard Time
- CT - Central Time
- MDT - Mountain Daylight Time
- EAST - Easter Island Standard Time
- GALT - Galapagos Time
- S - Sierra Time Zone
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
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico

Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Atlantic Daylight Time (ADT).
End: Atlantic Standard Time (AST) has ended on Sunday, March 9, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, March 9, 2025, 3:00 am local daylight time instead. Standard time ends annually the on second Sunday of March.
Start: Atlantic Standard Time (AST) starts on Sunday, November 2, 2025 at 2:00 am local time and clocks are set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually the on first Sunday of November.
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
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- Argentina Standard Time - UTC -3
- Armenia Standard Time - UTC +4
- Azores Summer Time - UTC +0
- Apia Standard Time - UTC +13
- 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