Time zone · Oceania
ACDT
Australian Central Daylight Time
Australian Central Daylight Time (ACDT) covers South Australia and parts of New South Wales, built around Adelaide and Broken Hill. ACDT is UTC+10:30, one hour ahead of Australian Central Standard Time (UTC+09:30), which clocks return to outside daylight saving. Both are half-hour offsets, found in only a few places on Earth. Living or collaborating here means your meeting invites need to respect both DST and that quirky 30‑minute jog.
Thursday, October 15, 2026
Current offset
UTC+10:30
Daylight · ACDT
Daylight saving
Active
Reverts 4 Apr 2027
IANA zones
2
2 observe DST, 0 don't
DST offset
—
No summer variant
About ACDT
Standard time, with a summer shift.
Australian Central Daylight Time (ACDT) covers South Australia and parts of New South Wales, built around Adelaide and Broken Hill. ACDT is UTC+10:30, one hour ahead of Australian Central Standard Time (UTC+09:30), which clocks return to outside daylight saving. Both are half-hour offsets, found in only a few places on Earth. Living or collaborating here means your meeting invites need to respect both DST and that quirky 30‑minute jog.
IANA zones · the technical identifiers
The 2 zones that resolve to ACDT.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Cities across ACDT
Local time, city by city.
1 city
Where ACDT is used
One country.
Convert
ACDT to the world's clocks.
Frequently asked questions
Common questions about ACDT, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- Which places follow Australian Central Time?
- Australian Central Daylight Time is kept by Adelaide (South Australia) and Broken Hill (New South Wales); Darwin uses Central Standard Time all year. The region is unusual because its offset is on the half hour: UTC+09:30 in winter and UTC+10:30 in summer.
- When do clocks change?
- Clocks move forward an hour to ACDT at 2:00 a.m. on the first Sunday in October and back to ACST at 3:00 a.m. on the first Sunday in April.
- Is Australian Central Time a full‑hour offset?
- No — outside daylight saving the offset is UTC+09:30, and during daylight saving it is UTC+10:30. It makes time math a little more interesting.
- Does the whole region observe daylight saving?
- Every listed zone in Australian Central Time flips between standard and daylight saving together, so you never get out of sync inside this time region.
- Which city represents this time zone?
- Adelaide is the representative city for this time region. Its clocks follow the same half‑hour dance with daylight saving.
- Where else uses this unusual offset?
- Only a few regions on Earth use a half‑hour offset, and Australian Central Time is one of them — India and Iran also use half-hour offsets.
- What’s tricky about scheduling here?
- You must remember both daylight saving and the 30‑minute oddity. A meeting at noon here lands on the half hour in cities with whole-hour offsets, such as Sydney, Tokyo or London.
Source: IANA tzdb2026d · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
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