Australia uses three main time zones: Australian Western Standard Time (AWST; UTC+08:00), Australian Central Standard Time (ACST; UTC+09:30) and Australian Eastern Standard Time (AEST; UTC+10:00).
Time is regulated by the individual state governments,Daylight Saving in New South Wales Lawlink NSW. Retrieved 28 January 2012 some of which observe daylight saving time (DST). Daylight saving time (+1 hour) is used between the first Sunday in October and the first Sunday in April in jurisdictions in the south and south-east: New South Wales, Victoria, Tasmania, Jervis Bay Territory and the Australian Capital Territory switch to the Australian Eastern Daylight Saving Time (AEDT; UTC+11:00), and South Australia switches to the Australian Central Daylight Saving Time (ACDT; UTC+10:30).
Standard time was introduced in the 1890s when all of the Australian colonies adopted it. Before the switch to standard time zones, each local city or town was free to determine its local time, called local mean time. Western Australia uses Western Standard Time; South Australia and the Northern Territory use Central Standard Time; while New South Wales, Queensland, Tasmania, Victoria, Jervis Bay Territory and the Australian Capital Territory use Eastern Standard Time. Daylight saving time is not used in Western Australia, the Northern Territory, or Queensland.
The Cocos (Keeling) Islands uses UTC+06:30 year round, Christmas Island uses UTC+07:00 year round, while Norfolk Island uses UTC+11:00 as standard time and UTC+12:00 as daylight saving time.
History The first serious proposal for Australian standard time came in the form of a paper inspired by Sandford Fleming's Canadian system of uniform time zones which Sir Charles Todd, the builder of the Overland Telegraph and South Australian Postmaster-General and an advocate for standard time in Australia, presented to the Intercolonial Postal Conference in Sydney in 1891. Before standardisation, most of the colonies had previously followed their own times, based upon the times of their capital cities as set at the local observatory. Todd's notion that the whole of Australia could be governed by a single uniform time, based on the 135th meridian, was a departure from the principles of Fleming's Canadian scheme; the idea was not well received, and it was eventually Queensland Postmaster-General W. H. Wilson's less radical proposal to divide Australia into three one-hourly time zones that won support on the 1893 Conference. On the same year, the Standard of Time Bill, enacting this proposal, passed through all the colonial parliaments without amendment and almost without debate.
Two years later, the colonies enacted time zone legislation, which took effect in February 1895. The clocks were set ahead of GMT by eight hours in Western Australia, by nine hours in South Australia (and the Northern Territory, which it governed); and by 10 hours in New South Wales, Victoria, Queensland and Tasmania. The three time zones became known as Western Standard Time, Central Standard Time, and Eastern Standard Time. Broken Hill in the far west of New South Wales (strictly speaking, the county of Yancowinna) also adopted Central Standard Time due to it being connected at the time by rail to Adelaide but not Sydney. The Australian colonies were among the last English-speaking countries to adopt the new system of standard time.
In May 1899, in a break with the common international practice of setting one-hour intervals between adjacent time zones, South Australia advanced Central Standard Time by thirty minutes after lobbying by businesses who wanted to be closer to Melbourne time and cricketers and footballers who wanted more daylight to practice in the evenings. It also meant that South Australia became one of only a few places in the world which uses a time-zone meridian located outside of its geographical boundaries, and one of the very few not a whole number of hours different from its neighbors. Attempts to undo this change in 1986 and 1994 failed.
In 1911, when the Northern Territory was separated from South Australia and placed under the jurisdiction of the Federal Government, the Northern Territory kept Central Standard Time. Likewise, when the Australian Capital Territory and Jervis Bay Territory were broken off from New South Wales, they retained Eastern Standard Time.
Since 1899, the only major changes in Australian time zones have been setting of clocks half an hour later than Eastern time (GMT plus 10:30) on the territory of Lord Howe Island and Norfolk Island changing from UTC+11:30 to UTC+11:00 on 4 October 2015.
Civil time and legislation Though the governments of the states and territories have the power to legislate variations in time, the standard time within each of these is set related to Coordinated Universal Time (UTC) as determined by the International Bureau of Weights and Measures and set by section 8AA of the National Measurement Act 1960 of the Commonwealth.
Australia has kept a version of the UTC atomic time scale since the 1990s, but Greenwich Mean Time (GMT) remained the formal basis for the standard times of all of the states until 2005. In November 2004, the state and territory attorneys-general endorsed a proposal from the Australian National Measurement Institute to adopt UTC as the standard of all Australian standard times, thereby eliminating the effects of slight variations in the rate of rotation of the Earth that are inherent in mean solar time. All jurisdictions have adopted the UTC standard, starting on 1 September 2005.
In Victoria, South Australia, Tasmania and the ACT, the starting and ending dates of daylight saving times are officially determined by proclamations, declarations, or regulation made by the State Governor or responsible minister. Such instruments may be valid for only the current year, and so this section generally only refers to the legislation. In New South Wales and Western Australia, the starting and ending dates, if any, are to be set by legislation.
Australian Western Standard Time (AWST) – UTC+08:00
Western Australia – Originally set relative to GMT by the . Several localities have declared their own time zones: Arubiddy Time/EBO Time These have no commercial or legal status.
Australian Central Standard Time (ACST) – UTC+09:30 South Australia – Standard Time Act 2009 and the Daylight Saving Act 1971 Several localities have declared their own time zones: Australian Central Western Standard Time (ACWST) These have no commercial or legal status. Northern Territory – Standard Time Act 2005
Australian Eastern Standard Time (AEST) – UTC+10:00 Queensland – Standard Time Act 1894 New South Wales – Standard Time Act 1987 Australian Capital Territory and Jervis Bay Territory – Standard Time and Summer Time Act 1972 Victoria – Summer Time Act 1972 (No. 8297), replacing the Daylight Saving Act 1971 (No. 8159). Originally set from 1 February 1895 by the Standard Time Act 1895 (No. 1370). The Justice Legislation (Amendment) Act 2005 (No. 17 of 2005) changed the basis from GMT to UTC. Tasmania – Standard Time Act 1895 and the Daylight Saving Act 2007
Daylight saving time (DST)
The choice of whether to use DST is a matter for the governments of the individual states and territories. However, during World War I and World War II all states and territories used daylight saving time (DST). In 1968 Tasmania became the first state to use DST in peacetime, followed in 1971 by New South Wales, Victoria, Queensland, South Australia, and the Australian Capital Territory. Queensland abandoned DST in 1972. Western Australia and the Northern Territory did not adopt it. Queensland and Western Australia have occasionally used DST since then during trial periods.
The main DST zones are the following: (Australian) Central Daylight Saving Time (ACDT or CDST) – UTC+10:30, in South Australia and Broken Hill, New South Wales (Australian) Eastern Daylight Saving Time (AEDT or EDST) – UTC+11:00, in New South Wales, the ACT, Victoria, and Tasmania
During the usual periods of DST, the three standard time zones in Australia become five zones. This includes the areas that do not observe DST: Western Australia (UTC+08:00), the Northern Territory (UTC+09:30), and Queensland (UTC+10:00).
The change to and from DST takes place at 02:00 local standard time on the appropriate Sunday. Until 2008, DST usually began on the last Sunday in October, and ended on the last Sunday in March. However, Tasmania, given its latitude further south, began DST earlier, on the first Sunday in October, and ended it later, on the first Sunday of April.
On 12 April 2007, New South Wales, Victoria, Tasmania, and the ACT agreed to common beginning and ending dates for DST from 2008. DST in these states and South Australia began on the first Sunday in October and ended on the first Sunday in April. Western Australia was then the only state to use DST from the last Sunday in October to the last Sunday in March, but it abolished DST in 2009.
State/territory Start of DST End of DST Western Australia Queensland Northern Territory South Australia first Sunday in October first Sunday in April New South Wales Australian Capital Territory Jervis Bay Territory Victoria Tasmania
Anomalies
Unlike the rest of mainland New South Wales, Broken Hill and the surrounding region (Yancowinna County) observes Australian Central Standard Time (UTC+09:30), a time zone it shares with nearby South Australia and the Northern Territory.
Heron Island, off the coast of Gladstone in Queensland, for decades had two time zones: the island resort followed DST all year round, whereas the Marine Research Centre and the Parks and Wildlife office on the island remained on Eastern Standard Time. The resort ceased this practice in 2014 in favour of observing the same time as the rest of Queensland, explaining that this was to "simplify our arrival and departures".Heron Island, Facebook post, 6 April 2014 Resort manager Alistair Cooray in 2007 said that no-one was sure how the time zone came about. 'I believe it started in the late 1950s early 1960s as a way to give the guests a bit more daylight time on the island and no-one knows for sure though.
Lord Howe Island, part of the state of New South Wales but east of the Australian mainland in the Pacific Ocean, uses UTC+10:30 during the winter months (30 minutes ahead of the eastern states), but advances to UTC+11:00 in summer (the same time as the rest of New South Wales except Yancowinna County).
A compromise between Western and Central time (UTC+08:45, without DST), also known as Central Western Standard Time, is unofficially used in one area in the southeastern corner of Western Australia and one roadhouse in South Australia. Towns east of Caiguna on the Eyre Highway (including Eucla, Cocklebiddy, Madura, Mundrabilla and Border Village, just over the border into South Australia), follow "CWT" instead of Western Australian time. The total population of that area is estimated at 200 people.
Until 1 July 2024, when they all switched to using AWST, a number of small Aboriginal communities in the Ngaanyatjarra lands of Outback Western Australia also followed UTC+09:30 rather than UTC+08. They included Blackstone, Irrunytju, Warakurna, Wanarn, Kiwirrkurra, and Tjukurla. Giles Weather Station, which is near Warakurna, uses ACST for weather observations, including daylight saving.
The Indian Pacific train has its own time zone—a so-called "train time" when travelling between Kalgoorlie, Western Australia and Port Augusta, South Australia—which was at UTC+09:00 hours during November 2005 when DST was observed in the eastern and southern states.
External territories Australia's external territories follow different time zones.