IANA tz database · zone identifier

Australia/Darwin

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+09:30Abbreviation ACSTNo DST — never observed
Time in Australia/Darwin☀ Daylight
08:28:38
Thursday, July 16, 2026
Offset
UTC+09:30
Abbreviation
ACST
DST
No DST

Current offset

UTC+09:30

same year-round

Abbreviation

ACST

used year-round

DST behaviour

Never

has never observed daylight saving

Country

🇦🇺 Australia

ISO 3166: AU · view country page →

Using this identifier

The string to put in your code.

Australia/Darwin 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 ACST or +09:30 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

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

Offset & DST behaviour

One offset,
82 years.

Australia/Darwin has kept UTC+09:30 year-round since 26 March 1944 — no daylight saving and no offset changes on record since. It is among the most stable identifiers in the database.

Every offset this zone has kept

+08:43:20UTC+09:30 · UNCHANGED 26 March 1944 NOW

Keeping this offset since

26 March 1944

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC + 9:30h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAustralia/Darwin
ISO country codeAU🇦🇺 Australia
Reference coordinates12.47°S, 130.83°Etz database reference point
Standard offsetUTC+09:30abbreviation ACST
Daylight offset—daylight saving has never been observed

Where it applies

One of Australia's 12 zones.

🇦🇺
Australia

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

Country page →

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/Darwin?
Australia/Darwin is UTC+09:30, year-round. The offset never changes because the zone does not observe daylight saving time.
Does Australia/Darwin observe daylight saving time?
No. Australia/Darwin has never observed DST — it has kept UTC+09:30 continuously since 26 March 1944.
Which country uses Australia/Darwin?
Australia. It is one of 12 IANA zones covering the country.
Is Australia/Darwin the same as ACST?
Australia/Darwin is one of the IANA zones that keeps Australian Central Standard Time (ACST). Use Australia/Darwin in software — ACST is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Everything on this page — offset, abbreviation, DST rules, coordinates — from one endpoint, always current with the latest tzdb release.

GET /v1/timezones Live

countries, cities, convert, DST transitions coming next.

Get your free API key →
// this identifier, resolved live
GET /v1/timezones?iana=Australia/Darwin
{
"iana": "Australia/Darwin",
"utc_offset": "+09:30",
"abbreviation": "ACST",
"observes_dst": false,
"country": "AU"
}