Convert ACDT to GMT
GMT is 10 hours 30 minutes behind ACDT. ACDT is UTC+10:30 and GMT is UTC+0.
Right now: ACDT · GMT
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between ACDT and GMT. Someone has to take an early or late call — or use asynchronous communication instead.
| ACDT | GMT | Suitable? |
|---|---|---|
| 9:00 AM | 10:30 PM (previous day) | outside 9–5 |
| 10:00 AM | 11:30 PM (previous day) | outside 9–5 |
| 11:00 AM | 12:30 AM | outside 9–5 |
| 12:00 PM | 1:30 AM | outside 9–5 |
| 1:00 PM | 2:30 AM | outside 9–5 |
| 2:00 PM | 3:30 AM | outside 9–5 |
| 3:00 PM | 4:30 AM | outside 9–5 |
| 4:00 PM | 5:30 AM | outside 9–5 |
| 5:00 PM | 6:30 AM | outside 9–5 |
ACDT to GMT conversion table
| ACDT | GMT |
|---|---|
| 12:00 AM | 1:30 PM (previous day) |
| 1:00 AM | 2:30 PM (previous day) |
| 2:00 AM | 3:30 PM (previous day) |
| 3:00 AM | 4:30 PM (previous day) |
| 4:00 AM | 5:30 PM (previous day) |
| 5:00 AM | 6:30 PM (previous day) |
| 6:00 AM | 7:30 PM (previous day) |
| 7:00 AM | 8:30 PM (previous day) |
| 8:00 AM | 9:30 PM (previous day) |
| 9:00 AM | 10:30 PM (previous day) |
| 10:00 AM | 11:30 PM (previous day) |
| 11:00 AM | 12:30 AM |
| 12:00 PM | 1:30 AM |
| 1:00 PM | 2:30 AM |
| 2:00 PM | 3:30 AM |
| 3:00 PM | 4:30 AM |
| 4:00 PM | 5:30 AM |
| 5:00 PM | 6:30 AM |
| 6:00 PM | 7:30 AM |
| 7:00 PM | 8:30 AM |
| 8:00 PM | 9:30 AM |
| 9:00 PM | 10:30 AM |
| 10:00 PM | 11:30 AM |
| 11:00 PM | 12:30 PM |
About ACDT
Australian Central Daylight Time (ACDT) is UTC+10:30. It is used in Adelaide in summer.
Australian Central Daylight Time is UTC+10:30, what South Australia keeps from October to April. Darwin stays on ACST through the summer, so for those months two cities in the same nominal zone are an hour apart — the only reason to be precise about which of the two abbreviations a meeting invitation carries.
About GMT
Greenwich Mean Time (GMT) is UTC+0. It is used in the UK and Ireland in winter, Portugal, Iceland and much of West Africa.
The trap with GMT is that the United Kingdom is not on it for most of the year. From late March to late October the UK runs BST, UTC+1, so a meeting agreed "10am GMT" with a London colleague in July is an hour out unless both parties meant the abbreviation literally. Broadcasters and airlines avoid the ambiguity by saying UTC. GMT itself is fixed at UTC+0 and does not shift; it is the UK's clocks that move away from it and back.
Does this gap change with the seasons?
This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on GMT switches to BST (UTC+1) from late March to late October. So the 10.5-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.
ACDT does not shift, so the whole change comes from one side. A recurring meeting fixed in ACDT will appear to move by an hour for everyone on the other side, twice a year, without anyone changing anything.
This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.
Frequently asked questions
What time is 9:00 AM ACDT in GMT?
9:00 AM ACDT is 10:30 PM GMT (previous day).
Is GMT ahead of ACDT?
GMT is 10 hours 30 minutes behind ACDT.
Which time zone does this use?
ACDT is UTC+10:30 and GMT is UTC+0. Both abbreviations denote a single fixed offset, so this conversion never shifts with daylight saving — what changes is which abbreviation a place is using at the time.