CST to ACST time conversion
ACST is 15 hours 30 minutes ahead of CST.
CST is always UTC-6. Right now most places that use CST are on CDT (UTC-5): ACST is 14 hours 30 minutes ahead of CDT.
ACST is always UTC+9:30. Right now most places that use ACST are on ACDT (UTC+10:30): ACDT is 16 hours 30 minutes ahead of CST.
Time difference with your location
CST is 6 hours behind UTC. Compare with your local time →
Choose a date and time
Choose the local time in CST to convert it to ACST on that date.
Skipped clock-change times are unavailable; a repeated time uses its first occurrence.
24-hour conversion chart · CST → ACST
This table converts each hour in CST to ACST on 2026-10-21.
- Working hours
- Outside working hours
- Night hours
| CST | ACST | Shared working hours |
|---|---|---|
| 00:0012:00 AM | 15:303:30 PM | |
| 01:001:00 AM | 16:304:30 PM | |
| 02:002:00 AM | 17:305:30 PM | |
| 03:003:00 AM | 18:306:30 PM | |
| 04:004:00 AM | 19:307:30 PM | |
| 05:005:00 AM | 20:308:30 PM | |
| 06:006:00 AM | 21:309:30 PM | |
| 07:007:00 AM | 22:3010:30 PM | |
| 08:008:00 AM | 23:3011:30 PM | |
| 09:009:00 AM | 00:3012:30 AM +1 day | |
| 10:0010:00 AM | 01:301:30 AM +1 day | |
| 11:0011:00 AM | 02:302:30 AM +1 day | |
| 12:0012:00 PM | 03:303:30 AM +1 day | |
| 13:001:00 PM | 04:304:30 AM +1 day | |
| 14:002:00 PM | 05:305:30 AM +1 day | |
| 15:003:00 PM | 06:306:30 AM +1 day | |
| 16:004:00 PM | 07:307:30 AM +1 day | |
| 17:005:00 PM | 08:308:30 AM +1 day | ✓ |
| 18:006:00 PM | 09:309:30 AM +1 day | |
| 19:007:00 PM | 10:3010:30 AM +1 day | |
| 20:008:00 PM | 11:3011:30 AM +1 day | |
| 21:009:00 PM | 12:3012:30 PM +1 day | |
| 22:0010:00 PM | 13:301:30 PM +1 day | |
| 23:0011:00 PM | 14:302:30 PM +1 day |
Quick conversion examples
These examples use CST (UTC-6) and ACST (UTC+9:30); choosing a date applies the local clock changes.
Conversion formula: ACST = CST + 15h30 · ACDT = CST + 16h30 · ACDT = CDT + 15h30 · CDT + 14h30.
| CST | ACST |
|---|---|
| 6:00 AM CST | = 9:30 PM ACST |
| 7:00 AM CST | = 10:30 PM ACST |
| 8:00 AM CST | = 11:30 PM ACST |
| 9:00 AM CST | = 12:30 AM ACST (+1 day) |
| 10:00 AM CST | = 1:30 AM ACST (+1 day) |
| 12:00 PM CST | = 3:30 AM ACST (+1 day) |
| 3:00 PM CST | = 6:30 AM ACST (+1 day) |
| 5:00 PM CST | = 8:30 AM ACST (+1 day) |
| 6:00 PM CST | = 9:30 AM ACST (+1 day) |
| 8:00 PM CST | = 11:30 AM ACST (+1 day) |
Overlapping meeting hours
The 08:00–18:00 working day in CST and ACST overlaps for 1 hour 30 minutes on 2026-10-21.
- Shared working hours
- 16:30–18:00 CST · 08:00–09:30 ACST
Clock changes on both sides, 2026–2028
CST and ACST have the following local clock changes in 2026–2028; all times in the table are local to that side.
| Year | CST | ACST |
|---|---|---|
| 2026 | · 02:00 → 03:00 · 02:00 → 01:00 | · 03:00 → 02:00 · 02:00 → 03:00 |
| 2027 | · 02:00 → 03:00 · 02:00 → 01:00 | · 03:00 → 02:00 · 02:00 → 03:00 |
| 2028 | · 02:00 → 03:00 · 02:00 → 01:00 | · 03:00 → 02:00 · 02:00 → 03:00 |
At the start of 2026, ACDT is 16 hours 30 minutes ahead of CST. The difference changes during the following periods.
- From 2026-03-08 03:00 CDT until 2026-04-04 11:30 CDT, ACDT is 15 hours 30 minutes ahead of CDT.
- From 2026-04-04 11:30 CDT until 2026-10-03 11:30 CDT, ACST is 14 hours 30 minutes ahead of CDT.
- From 2026-10-03 11:30 CDT until 2026-11-01 01:00 CST, ACDT is 15 hours 30 minutes ahead of CDT.
- From 2027-03-14 03:00 CDT until 2027-04-03 11:30 CDT, ACDT is 15 hours 30 minutes ahead of CDT.
- From 2027-04-03 11:30 CDT until 2027-10-02 11:30 CDT, ACST is 14 hours 30 minutes ahead of CDT.
- From 2027-10-02 11:30 CDT until 2027-11-07 01:00 CST, ACDT is 15 hours 30 minutes ahead of CDT.
- From 2028-03-12 03:00 CDT until 2028-04-01 11:30 CDT, ACDT is 15 hours 30 minutes ahead of CDT.
- From 2028-04-01 11:30 CDT until 2028-09-30 11:30 CDT, ACST is 14 hours 30 minutes ahead of CDT.
- From 2028-09-30 11:30 CDT until 2028-11-05 01:00 CST, ACDT is 15 hours 30 minutes ahead of CDT.
Frequently asked questions
What time is 9 AM CST in ACST?
9:00 AM CST = 12:30 AM ACST (+1 day), using UTC-6 and UTC+9:30. Choose a date above for the seasonal local time.
Does the time difference between CST and ACST change during the year?
Yes. During 2026–2028: ACST is 14 hours 30 minutes ahead of CST; ACST is 15 hours 30 minutes ahead of CST; ACST is 16 hours 30 minutes ahead of CST. The clock-change table gives the dates for both sides.
How do I tell whether it is day or night in ACST?
Read the ACST clock above: this guide counts 06:00–18:00 local time as daytime and the rest as nighttime, without using sunrise and sunset.
What is the best time to call between CST and ACST?
The shared 08:00–18:00 working window is 16:30–18:00 CST / 08:00–09:30 ACST, a total of 1 hour 30 minutes.
What is the time difference between CST and ACST now?
Right now, ACST is 15 hours 30 minutes ahead of CST. Conversion formula: ACST = CST + 15h30 · ACDT = CST + 16h30 · ACDT = CDT + 15h30 · CDT + 14h30.