Australia’s Weird Little Time Zone

Continental Australia is divided into three standard time zones, Western, Central and Eastern. It’s pretty simple to understand even bearing in mind that Australian Central Standard Time tracks to the half-hour (UTC+9:30). Individual Australian states and territories determine whether to recognise Daylight Saving Time (DST) or not. Far-flung Australian island territories and its Antarctic stations add a few more complexities. Overall, Australian time is fairly straightforward and understandable.

However Australia also has an unofficial but de facto hybrid time zone called “Australian Central Western Standard Time” (ACWST), which is set halfway between the official Western and Central times. With Western Time at UTC+8:00 and Central Time at UTC+9:30, splitting the difference makes the so-called Central Western Time UTC+8:45. Yes, a time zone that’s based not on the hour or the half-hour, but on the quarter hour!

This is quite rare, something found nowhere else except Nepal and in a few small, isolated corners of the globe. Visitors entering or leaving ACWST have to remember to set their watches in the proper direction either forward or back by 45 minutes. One of my very favorite websites, the Degree Confluence Project, includes a photograph of a highway sign that reminds travelers to account for this peculiarity.

ACWST is observed only in a tiny sliver in the far southeastern corner of Western Australia along the Eyre Highway, extending from just outside of Caiguna to about 50 metres across the South Australia state line to encompass Border Village, for a total length of about 340 kilometres. In addition to the map I drew above you can also see the ACWST western and eastern boundaries on this map provided by the Shire of Dundas in Western Australia. The northern boundary is less precise but it doesn’t really matter. This is part of the Nullarbor Plain, a vast, dry, flat, expanse of scrubland and not much else besides nature. Time doesn’t really matter in that immense empty acreage north of the Eyre Highway.

Roadhouse settlements hug the highway on a long string with as much as a hundred kilometres between them. Places that follow ACWST include:

  • Cocklebiddy, with its world-class cave systems
  • Madura, and its panoramic views from the Hampton Tablelands
  • Mundrabilla, where pioneers first settled on the Nullarbor in 1872
  • Eucla, with its old telegraph station ruin and oddly enough, a golf course
  • Border Village, which as the name implies, sits just across the border and has the distinction of being the only spot in South Australia to follow ACWST

Perhaps only a couple hundred people live within the narrow ACWST strip. This of course made it much easier for them to agree upon a standard time. A couple hundred people can probably come to consensus on just about anything, apparently even the complete departure from a standard time others say should apply to them. That doesn’t concern them. They set their clocks as they please. It’s such a small population that the government turns a blind eye to it and allows ACWST to continue albeit without official sanction.

It’s not as illogical as it seems on the surface, and in fact it makes a lot of sense. The hour and a half gap at the border between Western and Central time provides plenty of incentive on its own, but it got even worse in the summer when South Australia used to switch to Daylight Saving Time but Western Australia did not. When that happened the gap became an incredible two and a half hours just by crossing from one state to another. Western Australia has been following Daylight Saving Time on a trial basis since the Spring of 2006 so it’s less of an issue at the moment but it’s supposed to be revisited in 2009 and the immense gap could return. Meanwhile ACWST continues to be followed regardless of official sanction.