CST to AST Converter
AST is 2 hours ahead of CST. 9:00 AM CST = 11:00 AM AST.
AST is 2 hours ahead of CST. To convert CST to AST, add 2 hours to the CST time: 9:00 AM CST = 11:00 AM AST.
CST (Central Time) is used in Chicago, Dallas, Houston, Minneapolis, New Orleans, Winnipeg; Mexico City and Central America use UTC−6 all year. AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year).
CST here means North American Central Standard Time, not China Standard Time. AST here is Atlantic Standard Time, not Arabia Standard Time.
CST to AST time conversion table
CST to AST on 6 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| CST | AST | Day |
|---|---|---|
| 12:00 AM CST | 2:00 AM AST | night |
| 1:00 AM CST | 3:00 AM AST | night |
| 2:00 AM CST | 4:00 AM AST | night |
| 3:00 AM CST | 5:00 AM AST | night |
| 4:00 AM CST | 6:00 AM AST | — |
| 5:00 AM CST | 7:00 AM AST | — |
| 6:00 AM CST | 8:00 AM AST | — |
| 7:00 AM CST | 9:00 AM AST | — |
| 8:00 AM CST | 10:00 AM AST | — |
| 9:00 AM CST | 11:00 AM AST | work hours |
| 10:00 AM CST | 12:00 PM AST | work hours |
| 11:00 AM CST | 1:00 PM AST | work hours |
| 12:00 PM CST | 2:00 PM AST | work hours |
| 1:00 PM CST | 3:00 PM AST | work hours |
| 2:00 PM CST | 4:00 PM AST | work hours |
| 3:00 PM CST | 5:00 PM AST | — |
| 4:00 PM CST | 6:00 PM AST | — |
| 5:00 PM CST | 7:00 PM AST | — |
| 6:00 PM CST | 8:00 PM AST | — |
| 7:00 PM CST | 9:00 PM AST | — |
| 8:00 PM CST | 10:00 PM AST | night |
| 9:00 PM CST | 11:00 PM AST | night |
| 10:00 PM CST | 12:00 AM AST | next day |
| 11:00 PM CST | 1:00 AM AST | next day |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert CST to AST
Add 2 hours to the CST time to get AST.
Example: 9:00 AM CST = 11:00 AM AST.
Across midnight: 10:00 PM CST = 12:00 AM AST (next day). The date changes, so always check the day as well as the hour.
Time difference between CST and AST
The time difference between CST and AST is 2 hours all year – AST is ahead of CST.
CST and AST during daylight saving time
- CST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from CST (UTC−6) to CDT (UTC−5).
- AST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from AST (UTC−4) to ADT (UTC−3).
Best time for a meeting between CST and AST
CST and AST share 6 hours of the 9 AM–5 PM working day. Any time between 9:00 AM and 3:00 PM CST lands between 11:00 AM and 5:00 PM AST, inside working hours for both.
CST to AST FAQ
What is the time difference between CST and AST?
AST is 2 hours ahead of CST all year. 9:00 AM CST = 11:00 AM AST.
What is 9 AM CST in AST?
9:00 AM CST is 11:00 AM AST.
What is 12 PM (noon) CST in AST?
12:00 PM CST is 2:00 PM AST.
Is AST ahead of or behind CST?
AST is 2 hours ahead of CST, so it is later in AST than in CST.
Does CST change for daylight saving time?
Yes. CST next changes on 14 Mar 2027, when clocks go forward one hour from CST to CDT.
Does AST change for daylight saving time?
Yes. AST next changes on 14 Mar 2027, when clocks go forward one hour from AST to ADT.
What is the best time for a meeting between CST and AST?
CST and AST share 6 hours of the 9 AM–5 PM working day. Any time between 9:00 AM and 3:00 PM CST lands between 11:00 AM and 5:00 PM AST, inside working hours for both.
Is CT the same as CST?
CST is the winter (standard) name of Central Time (CT). From March to November the same clocks are called CDT. This converter always uses the one in force on the date you choose.
Related conversions
Convert AST to CST
Convert CST to other time zones
Convert other time zones to AST
Learn more
Updated 6 November 2026. Time zone data: IANA tz database.