IANA tz database · zone identifier

Australia/Adelaide

The IANA tz database identifier for Australian Central Standard Time in Australia. Store this string — not the abbreviation, not the offset — and your timestamps stay correct forever.

UTC+10:30Abbreviation ACDTObserves daylight saving
Time in Australia/Adelaide☾ Night
00:38:55
Friday, October 16, 2026
Offset
UTC+10:30
Abbreviation
ACDT
DST
Active

Current offset

UTC+10:30

standard UTC+09:30 · daylight UTC+10:30

Abbreviation

ACDT

the daylight-saving form

DST behaviour

Observes

changes clocks twice a year

Country

🇦🇺 Australia

ISO 3166: AU · view country page →

Using this identifier

The string to put in your code.

Australia/Adelaide is the identifier to use in code and config for this region. Every modern language, database, and OS resolves it through the same tz database, so the examples here behave identically everywhere.

Avoid storing ACDT or +10:30 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone
new Intl.DateTimeFormat('en-US', {
timeZone: 'Australia/Adelaide',
dateStyle: 'full', timeStyle: 'long'
}).format(new Date());

Offset & DST behaviour

Two offsets,
every year.

Australia/Adelaide alternates between ACST (UTC+09:30) and ACDT (UTC+10:30). Right now it is on ACDT; clocks fall back on 4 April 2027.

The year at a glance

ACDT · UTC+10:30ACST · UTC+09:304 Oct · +1h4 Apr · −1h Jan 2027 Dec

Technical record

The database entry, in full.

source: IANA tz database · release 2026e

IdentifierAustralia/Adelaide
ISO country codeAU🇦🇺 Australia
Reference coordinates34.92°S, 138.58°Etz database reference point
Standard offsetUTC+09:30abbreviation ACST
Daylight offsetUTC+10:30abbreviation ACDT
tzdb release2026edata current as of this IANA release

Where it applies

One of Australia's 12 zones.

Looking for travel-friendly info? See Adelaide or Australian Central Standard Time.

🇦🇺
Australia

28M people, 12 time zones — this identifier covers one of them.

Country page →
🇦🇺 Adelaide
00:38
00:38:55 · ACDT
pop. 1.4MACST

Related identifiers

Nearby in the database.

Same zone group · Australian Central Standard Time

other identifiers keeping ACST

Frequently asked questions

Answers specific to this identifier — generated from the database record. Can't find what you need? Email [email protected].

What UTC offset is Australia/Adelaide?
Australia/Adelaide is currently UTC+10:30 (ACDT). It alternates between UTC+09:30 in winter and UTC+10:30 in summer.
Does Australia/Adelaide observe daylight saving time?
Yes. Clocks fall back at the next transition on 4 April 2027, as they do twice every year.
Which country uses Australia/Adelaide?
Australia. It is one of 12 IANA zones covering the country.
Is Australia/Adelaide the same as ACST?
Australia/Adelaide is one of the IANA zones that keeps Australian Central Standard Time (ACST). Use Australia/Adelaide in software — ACST is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Its live offset, abbreviation, DST status and next clock change, plus its coordinates and country, from one endpoint.

GET /v1/timezones Live

Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.

Get your free API key → All endpoints Plans and pricing

Moving off WorldTimeAPI? Our drop-in replacement needs no key.

// this identifier, resolved live
GET /v1/timezones/Australia/Adelaide
{
"data": {
"iana": "Australia/Adelaide",
"observes_dst": true,
"country": { "code": "AU", "name": "Australia" },
"current": {
"utc_offset": "+10:30",
"abbreviation": "ACDT",
…
},
…
}
}