Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Australian Central Western Standard Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
None (Western Australia discontinued daylight saving experiments in 2009)
⬇️ Fall Back (Clocks Return)
None
Observing Jurisdictions & Subdivisions
1 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under ACWST:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
Serves trans-continental freight carriers, pastoral stations, and communications relay stations along the Nullarbor Plain.
Local Hours: 08:30 - 17:00 ACWST
UTC Window: 23:45 - 08:15 UTC
Major Cities in ACWST
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1957
ACWST was established informally by settlers and roadhouse operators along the 340-kilometer stretch of the Eyre Highway between Western and South Australia, sitting precisely 45 minutes ahead of Western Australia (UTC+8) and 45 minutes behind South Australia (UTC+9:30).
ACWST is one of only two official 45-minute UTC offsets in the world, the other being New Zealand's Chatham Islands (UTC+12:45).
Frequently Asked Questions about ACWST
What is ACWST?
ACWST stands for Australian Central Western Standard Time (UTC+8:45), an unusual 45-minute offset along the Nullarbor Plain.
Where is ACWST observed?
It is observed along the Eyre Highway in communities such as Eucla, Caiguna, Madura, and Mundrabilla.
Does ACWST use daylight saving?
No. The region stays on UTC+8:45 all year round.