What is GMT in ACST?
Australian Central Time is 9 hours 30 minutes ahead
Greenwich Mean Time is on UTC+0:00 and Australian Central Time is on UTC+9:30 right now. The gap changes during the year — see below.
- Time in Greenwich
- 2:56 am
- Time in Adelaide
- 12:26 pm
- Difference
- +9:30 h
- Next clock change
- October 3, 2026
Convert a time
ACST — Australian Central Time
11:30 am
Wed
When the difference changes
Greenwich Mean Time and Australian Central 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, 2026Australian Central Time is 9 hours 30 minutes ahead
- October 3, 2026 – April 3, 2027Australian Central Time is 10 hours 30 minutes ahead
- April 3, 2027 – October 2, 2027Australian Central Time is 9 hours 30 minutes ahead
- October 2, 2027 – onwardsAustralian Central Time is 10 hours 30 minutes ahead
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
Greenwich Mean Time
Greenwich Mean Time stays on GMT all year, so its offset from UTC never moves.
Australian Central Time
Clocks go forward one hour at 2am local time, becoming ACDT.
GMT to ACST conversion table
Every hour of Wednesday, September 23, 2026, converted from Greenwich Mean Time to Australian Central Time. 9 of the 24 hours fall on a different calendar day in Adelaide, which is marked.
- 12:00 am GMT
- 9:30 am ACST
- 1:00 am GMT
- 10:30 am ACST
- 2:00 am GMT
- 11:30 am ACST
- 3:00 am GMT
- 12:30 pm ACST
- 4:00 am GMT
- 1:30 pm ACST
- 5:00 am GMT
- 2:30 pm ACST
- 6:00 am GMT
- 3:30 pm ACST
- 7:00 am GMT
- 4:30 pm ACST
- 8:00 am GMT
- 5:30 pm ACST
- 9:00 am GMT
- 6:30 pm ACST
- 10:00 am GMT
- 7:30 pm ACST
- 11:00 am GMT
- 8:30 pm ACST
- 12:00 pm GMT
- 9:30 pm ACST
- 1:00 pm GMT
- 10:30 pm ACST
- 2:00 pm GMT
- 11:30 pm ACST
- 3:00 pm GMT
- 12:30 am ACST+1 day
- 4:00 pm GMT
- 1:30 am ACST+1 day
- 5:00 pm GMT
- 2:30 am ACST+1 day
- 6:00 pm GMT
- 3:30 am ACST+1 day
- 7:00 pm GMT
- 4:30 am ACST+1 day
- 8:00 pm GMT
- 5:30 am ACST+1 day
- 9:00 pm GMT
- 6:30 am ACST+1 day
- 10:00 pm GMT
- 7:30 am ACST+1 day
- 11:00 pm GMT
- 8:30 am ACST+1 day
Scheduling between the two
There is no overlap between a nine-to-six working day in Greenwich and one in Adelaide — the gap is too wide. A call has to sit early or late for one side. Early morning in Greenwich is the usual compromise, since that is late afternoon or evening in Adelaide.
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.
Australian Central Time (ACST) is used in South Australia and the Northern Territory, on a half-hour offset from the east coast