GMT to ACST converter
ACST is 10.5 hours ahead of GMT right now. Live clocks on both sides, a direct time input, the full 24-hour table with a permalink per hour, and the real daylight-saving state, computed from the IANA tz database on every request, never from a stored offset.
Convert an exact time type it, no sliders
Conversion runs in your browser against the same IANA rules the server uses, so it keeps working offline and nothing you type is sent anywhere.
Daylight saving right now
Australian Central Standard Time
Australia/Adelaide is currently on ACDT (UTC+10:30), its daylight-saving clock. That is not ACST. This page is named for the abbreviation people search for, and tells you the truth about which one is actually in force.
next change: Sun, 4 Apr 2027 02:00 local → ACST (178 days, clocks go back)
ACST is UTC+9:30, one of the handful of half-hour offsets still in daily use. Adelaide moves to ACDT (UTC+10:30) in the southern summer; Darwin stays on ACST.
Greenwich Mean Time
Etc/GMT is on GMT (UTC+00:00).
no clock change scheduled: fixed at UTC+00:00
GMT is UTC+0 and never shifts. The UK observes GMT in winter only: in summer it is on BST (UTC+1), so "GMT" on a British invite dated in July usually means BST.
Best time to call green = 09:00 to 18:00 on both sides
No overlap inside a 09:00 to 18:00 day on both sides. Someone has to take an early or late slot, and the table below shows exactly which hours are least bad.
GMT to ACST, hour by hour 6 October 2026 · every row is a permalink
| GMT | ACST | 12-hour | Day | Permalink |
|---|---|---|---|---|
| 00:00 | 10:30 ACDT | 10:30 AM | same day | 00:00 → |
| 01:00 | 11:30 ACDT | 11:30 AM | same day | 01:00 → |
| 02:00 | 12:30 ACDT | 12:30 PM | same day | 02:00 → |
| 03:00 | 13:30 ACDT | 1:30 PM | same day | 03:00 → |
| 04:00 | 14:30 ACDT | 2:30 PM | same day | 04:00 → |
| 05:00 | 15:30 ACDT | 3:30 PM | same day | 05:00 → |
| 06:00 | 16:30 ACDT | 4:30 PM | same day | 06:00 → |
| 07:00 | 17:30 ACDT | 5:30 PM | same day | 07:00 → |
| 08:00 | 18:30 ACDT | 6:30 PM | same day | 08:00 → |
| 09:00 | 19:30 ACDT | 7:30 PM | same day | 09:00 → |
| 10:00 | 20:30 ACDT | 8:30 PM | same day | 10:00 → |
| 11:00 | 21:30 ACDT | 9:30 PM | same day | 11:00 → |
| 12:00 | 22:30 ACDT | 10:30 PM | same day | 12:00 → |
| 13:00 | 23:30 ACDT | 11:30 PM | same day | 13:00 → |
| 14:00 | 00:30 ACDT | 12:30 AM | next day | 14:00 → |
| 15:00 | 01:30 ACDT | 1:30 AM | next day | 15:00 → |
| 16:00 | 02:30 ACDT | 2:30 AM | next day | 16:00 → |
| 17:00 | 03:30 ACDT | 3:30 AM | next day | 17:00 → |
| 18:00 | 04:30 ACDT | 4:30 AM | next day | 18:00 → |
| 19:00 | 05:30 ACDT | 5:30 AM | next day | 19:00 → |
| 20:00 | 06:30 ACDT | 6:30 AM | next day | 20:00 → |
| 21:00 | 07:30 ACDT | 7:30 AM | next day | 21:00 → |
| 22:00 | 08:30 ACDT | 8:30 AM | next day | 22:00 → |
| 23:00 | 09:30 ACDT | 9:30 AM | next day | 23:00 → |