What is CST in AST?
Atlantic Time is 2 hours ahead
Central Time is on UTC−5:00 and Atlantic Time is on UTC−3:00 right now. Both are on daylight saving, so their clocks read CDT and ADT. That gap holds all year, because both zones change their clocks together.
- Time in Chicago
- 9:55 pm
- Time in Halifax
- 11:55 pm
- Difference
- +2 h
- Next clock change
- November 1, 2026
Convert a time
ADT — Atlantic Time
11:00 pm
Tue
Daylight saving
Central Time
Clocks go back one hour at 2am local time, becoming CST.
Atlantic Time
Clocks go back one hour at 2am local time, becoming AST.
CST to AST conversion table
Every hour of Tuesday, September 22, 2026, converted from Central Time to Atlantic Time. 2 of the 24 hours fall on a different calendar day in Halifax, which is marked.
- 12:00 am CDT
- 2:00 am ADT
- 1:00 am CDT
- 3:00 am ADT
- 2:00 am CDT
- 4:00 am ADT
- 3:00 am CDT
- 5:00 am ADT
- 4:00 am CDT
- 6:00 am ADT
- 5:00 am CDT
- 7:00 am ADT
- 6:00 am CDT
- 8:00 am ADT
- 7:00 am CDT
- 9:00 am ADT
- 8:00 am CDT
- 10:00 am ADT
- 9:00 am CDT
- 11:00 am ADT
- 10:00 am CDT
- 12:00 pm ADT
- 11:00 am CDT
- 1:00 pm ADT
- 12:00 pm CDT
- 2:00 pm ADT
- 1:00 pm CDT
- 3:00 pm ADT
- 2:00 pm CDT
- 4:00 pm ADT
- 3:00 pm CDT
- 5:00 pm ADT
- 4:00 pm CDT
- 6:00 pm ADT
- 5:00 pm CDT
- 7:00 pm ADT
- 6:00 pm CDT
- 8:00 pm ADT
- 7:00 pm CDT
- 9:00 pm ADT
- 8:00 pm CDT
- 10:00 pm ADT
- 9:00 pm CDT
- 11:00 pm ADT
- 10:00 pm CDT
- 12:00 am ADT+1 day
- 11:00 pm CDT
- 1:00 am ADT+1 day
Scheduling between the two
Working hours overlap from 9:00 am to 4:00 pm CDT, which is 11:00 am to 6:00 pm ADT. Anything inside that window falls in the normal working day at both ends.
A note on CST: it can also mean China Standard Time (UTC+8) and Cuba Standard Time (UTC−5). This page means US Central Time.
A note on AST: it can also mean Arabia Standard Time (UTC+3). This page means Atlantic Time.
Central Time (CDT) is used in Dallas, Houston, Mexico City and Winnipeg
Atlantic Time (ADT) is used in Nova Scotia, New Brunswick and Puerto Rico