Time zone · Oceania
ACWST
Australian Central Western Standard Time
Australian Central Western Standard Time (ACWST) is a little-known UTC+08:45 offset used by a handful of remote settlements in Western Australia—most famously Eucla—sitting along the border where the longitudinal divide between Western and Central Australian time zones would otherwise run straight through communities that live, work and trade across the line.
Thursday, October 15, 2026
Current offset
UTC+08:45
Standard · +0845
Daylight saving
Not observed
Year-round standard time
IANA zones
1
None observe daylight saving
DST offset
—
No summer variant
About ACWST
A fixed, year-round offset.
Australian Central Western Standard Time (ACWST) is a little-known UTC+08:45 offset used by a handful of remote settlements in Western Australia—most famously Eucla—sitting along the border where the longitudinal divide between Western and Central Australian time zones would otherwise run straight through communities that live, work and trade across the line.
IANA zones · the technical identifiers
The zone that resolve to ACWST.
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.
Where ACWST is used
One country.
Convert
ACWST to the world's clocks.
Frequently asked questions
Common questions about ACWST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- Why is ACWST only UTC+08:45 instead of a round number?
- The +08:45 offset is a practical compromise between Australian Western Standard Time (+08:00) and Australian Central Standard Time (+09:30), created for communities whose daily life and commerce naturally span the border between these two time zones.
- Are there many places that use ACWST?
- Virtually none beyond Eucla and its immediate surroundings; it’s one of the world’s rarest time codes, representing a tiny pocket of Australia’s vast interior where local needs outweigh time-zone neatness.
- Does ACWST observe daylight saving time?
- Not any more. Eucla last used daylight saving (UTC+09:45) during Western Australia’s 2006–2009 trial, and has stayed on UTC+08:45 all year since March 2009.
- How long has Eucla been using this unusual offset?
- The time zone database records UTC+08:45 for Eucla since December 1895. It has never been an official legal time; local communities keep it by convention.
- What’s it like scheduling calls from ACWST?
- You’ll need an extra mental step: Eucla is 45 minutes ahead of Perth and 45 minutes behind Adelaide, or 1 hour 45 minutes behind Adelaide when South Australia is on daylight saving.
- Do maps show ACWST?
- Most maps just shade it under Western or Central, so it’s often invisible unless you specifically seek out time-zone boundary maps—a testament to its niche role in Australian geography.
- Why not just switch to a standard zone?
- Eucla’s social and economic ties sit between Perth and Adelaide; adopting a 45-minute offset neatly bridges those two spheres of influence without forcing the town to fully commit to one large city or the other.
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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