ACDT — Australian Central Daylight Time
ACDT is Australian Central Daylight Time, +10:30, used in Oceania. In code, use Australia/Adelaide rather than the abbreviation.
Australian Central Daylight Time · Oceania
09:56:13
Thursday, 13 August 2026
- abbreviation denotes
- +10:30
- in force right now
- ACST (UTC+09:30)
- use in code
- Australia/Adelaide
- next clock change
- 4 Oct 2026 03:00 → ACDT
Right now this zone is on ACST, not ACDT —
they are the same place at different times of year.
Use the IANA name, not the abbreviation
Python
from datetime import datetime
from zoneinfo import ZoneInfo
# right: an IANA zone carries the full history of rule changes
now = datetime.now(ZoneInfo("Australia/Adelaide"))
print(now.isoformat(), now.tzname())
# wrong: an abbreviation is not resolvable, and a hard-coded offset
# silently rots the next time the rules change
# now = datetime.now(timezone(timedelta(hours=...))) # don't
ACDT questions
What does ACDT stand for?
ACDT is Australian Central Daylight Time, +10:30, used in Oceania. The IANA zone to use in code is Australia/Adelaide.
What time is it in ACDT right now?
Australian Central Daylight Time: 09:56 on Thursday (ACST).
Which IANA timezone should I use instead of ACDT?
Australia/Adelaide for Australian Central Daylight Time. Date libraries cannot resolve bare abbreviations, and an abbreviation carries no daylight-saving history, so a stored offset silently rots when a government changes the rules.
Why does my computer show ACST instead of ACDT?
Because Australia/Adelaide is currently on ACST (UTC+09:30), its daylight-saving variant. ACDT (+10:30) applies during the other half of the year. Both names refer to the same place, one hour apart.