What is ACST in GMT?
Greenwich Mean Time is 9 hours 30 minutes behind
Australian Central Time is on UTC+9:30 and Greenwich Mean Time is on UTC+0:00 right now. The gap changes during the year — see below.
- Time in Adelaide
- 11:43 am
- Time in Greenwich
- 2:13 am
- Difference
- −9:30 h
- Next clock change
- October 3, 2026
Convert a time
GMT — Greenwich Mean Time
1:30 am
Wed
When the difference changes
Australian Central Time and Greenwich Mean Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:
- Now – October 3, 2026Greenwich Mean Time is 9 hours 30 minutes behind
- October 3, 2026 – April 3, 2027Greenwich Mean Time is 10 hours 30 minutes behind
- April 3, 2027 – October 2, 2027Greenwich Mean Time is 9 hours 30 minutes behind
- October 2, 2027 – onwardsGreenwich Mean Time is 10 hours 30 minutes behind
Periods shorter than a day are not listed: both zones change at 2am in their own local time, so there are a few hours on each transition date when the gap is briefly something else.
Daylight saving
Australian Central Time
Clocks go forward one hour at 2am local time, becoming ACDT.
Greenwich Mean Time
Greenwich Mean Time stays on GMT all year, so its offset from UTC never moves.
ACST to GMT conversion table
Every hour of Wednesday, September 23, 2026, converted from Australian Central Time to Greenwich Mean Time. 10 of the 24 hours fall on a different calendar day in Greenwich, which is marked.
- 12:00 am ACST
- 2:30 pm GMT−1 day
- 1:00 am ACST
- 3:30 pm GMT−1 day
- 2:00 am ACST
- 4:30 pm GMT−1 day
- 3:00 am ACST
- 5:30 pm GMT−1 day
- 4:00 am ACST
- 6:30 pm GMT−1 day
- 5:00 am ACST
- 7:30 pm GMT−1 day
- 6:00 am ACST
- 8:30 pm GMT−1 day
- 7:00 am ACST
- 9:30 pm GMT−1 day
- 8:00 am ACST
- 10:30 pm GMT−1 day
- 9:00 am ACST
- 11:30 pm GMT−1 day
- 10:00 am ACST
- 12:30 am GMT
- 11:00 am ACST
- 1:30 am GMT
- 12:00 pm ACST
- 2:30 am GMT
- 1:00 pm ACST
- 3:30 am GMT
- 2:00 pm ACST
- 4:30 am GMT
- 3:00 pm ACST
- 5:30 am GMT
- 4:00 pm ACST
- 6:30 am GMT
- 5:00 pm ACST
- 7:30 am GMT
- 6:00 pm ACST
- 8:30 am GMT
- 7:00 pm ACST
- 9:30 am GMT
- 8:00 pm ACST
- 10:30 am GMT
- 9:00 pm ACST
- 11:30 am GMT
- 10:00 pm ACST
- 12:30 pm GMT
- 11:00 pm ACST
- 1:30 pm GMT
Scheduling between the two
There is no overlap between a nine-to-six working day in Adelaide and one in Greenwich — the gap is too wide. A call has to sit early or late for one side. Early morning in Adelaide is the usual compromise, since that is late afternoon or evening in Greenwich.
Australian Central Time (ACST) is used in South Australia and the Northern Territory, on a half-hour offset from the east coast
Greenwich Mean Time (GMT) is used in as a fixed UTC+0 offset. Note that the UK itself leaves GMT every summer — see British Time below.