| Standard | DST | Zone | States/territories | |
|---|---|---|---|---|
| UTC+05:00 (year round) | HM | |||
| UTC+06:30 (year round) | Cocos | CC | ||
| UTC+07:00 (year round) | Christmas | CX | ||
| UTC+08:00 (year round) | Western | WA | ||
| UTC+08:45 (year round) | Central Western | (South-eastern WA &Border Village, SA) | ||
| UTC+09:30 (year round) | Central | NT | ||
| UTC+09:30 | UTC+10:30 | Central | SA,Broken Hill | |
| UTC+10:00 (year round) | Eastern | QLD | ||
| UTC+10:00 | UTC+11:00 | Eastern | NSW,TAS,VIC,ACT,JBT | |
| UTC+10:30 | UTC+11:00 | Lord Howe | Lord Howe Island | |
| UTC+11:00 | UTC+12:00 | Norfolk | Norfolk Island | |
Australia uses three maintime zones:Australian Eastern Standard Time (AEST;UTC+10:00),Australian Central Standard Time (ACST;UTC+09:30) andAustralian Western Standard Time (AWST;UTC+08:00).[1]
Time is regulated by the individualstate governments,[2] 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:
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, calledlocal mean time.Western Australia uses Western Standard Time;South Australia and theNorthern 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 currently used in Western Australia, the Northern Territory, or Queensland.
TheCocos (Keeling) Islands usesUTC+06:30 year round,Christmas Island usesUTC+07:00 year round, whileNorfolk Island usesUTC+11:00 as standard time andUTC+12:00 as daylight saving time.
The first serious proposal for Australian standard time came the form of a paper inspired bySandford Fleming's Canadian system of uniform time zones which SirCharles Todd, the builder of theOverland Telegraph and South AustralianPostmaster-General and an advocate for standard time in Australia, presented to the Intercolonial Postal Conference in Sydney in 1891. Before standardization, most of the colonies had previously followed their own times, based upon the times of their capital cities as set at the local observatory.[3]: 170 Todd's notion that the whole of Australia could be governed by a single uniform time, based on the135th meridian, was a departure from the principles of Fleming's Canadian scheme; the idea was not well received, and it was eventually Queensland Postmaster-GeneralW. 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.[3]: 171
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 inWestern Australia, by nine hours inSouth Australia (and theNorthern Territory, which it governed); and by 10 hours inNew South Wales,Victoria,Queensland andTasmania. The three time zones became known asWestern Standard Time,Central Standard Time, andEastern Standard Time.Broken Hill in the far west of New South Wales (strictly speaking, the county ofYancowinna) also adopted Central Standard Time due to it being connected at the time by rail toAdelaide but notSydney.[4] The Australian colonies were among the last English-speaking countries to adopt the new system of standard time.[3]: 169
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.[4] 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. Attempts to undo this change in 1986 and 1994 failed.[5][6][citation needed]
In 1911, when the Northern Territory was separated from South Australia and placed under the jurisdiction of theFederal Government, the Northern Territory kept Central Standard Time. Likewise, when theAustralian Capital Territory andJervis 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 ofLord Howe Island andNorfolk Island changing fromUTC+11:30 to UTC+11:00 on 4 October 2015.[7]
Though thegovernments of the states and territories have the power to legislate variations in time, the standard time within each of these is set related toCoordinated Universal Time (UTC) as determined by theInternational Bureau of Weights and Measures and set by section 8AA of theNational Measurement Act 1960[8] of theCommonwealth.
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 inmean 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 byproclamations, 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 Central Western Standard Time (ACWST) UTC+08:45
Arubiddy Time/EBO Time UTC+09:00
 |  |
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:
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 itslatitude 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.[21]
| State/territory | Start of DST | End of DST |
|---|---|---|
| Western Australia | N/A | |
| Queensland | ||
| Northern Territory | ||
| South Australia | first Sunday in October | first Sunday in April[22] |
| New South Wales | ||
| Australian Capital Territory | ||
| Jervis Bay Territory | ||
| Victoria | ||
| Tasmania | ||
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.[23]
Heron Island, 72 km (45 mi) off the coast off Gladstone in Queensland, for decades had two time zones: the island resort followed DST all year round, whereas theMarine 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".[24] 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.'"[25]
Lord Howe Island, part of the state of New South Wales but 600 kilometres (370 miles) 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), unofficially known asCentral Western Standard Time, is used in one area in the southeastern corner of Western Australia and oneroadhouse in South Australia. Towns east ofCaiguna on theEyre Highway (includingEucla,[26]Cocklebiddy,Madura,Mundrabilla andBorder 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.[27]
A number of small towns in Outback Western Australia also follow UTC+09:30 rather than UTC+08. These towns include Blackstone, Irrunytju, Warakurna, Wanarn, Kiwirrkurra, andTjukurla.[28]
TheIndian Pacific train has its own time zone—a so-called "train time" when travelling betweenKalgoorlie, Western Australia andPort Augusta, South Australia—which was at UTC+09:00 hours during November 2005 when DST was observed in the eastern and southern states.[29][30]
Australia's external territories follow different time zones.
| Territory | Standard | DST |
|---|---|---|
| Heard and McDonald Islands | UTC+05:00 | no DST |
| Cocos (Keeling) Islands CCT | UTC+06:30 | no DST |
| Christmas Island CXT | UTC+07:00 | no DST |
| Norfolk Island NFT/NFDT | UTC+11:00 | UTC+12:00 |
| Australian Antarctic Territory –Mawson | UTC+05:00 | no DST |
| Australian Antarctic Territory –Davis | UTC+07:00 | no DST |
| Australian Antarctic Territory –Casey | UTC+08:00 | no DST |
In 2000, all of the eastern jurisdictions that normally observe DST—New South Wales, Victoria, the ACT, and Tasmania—began DST early because of theSummer Olympic Games held in Sydney. These jurisdictions moved to DST on 27 August 2000. South Australians did not change their clocks until the usual date, which was 29 October 2000.
In 2006, all of the states that followed DST (the above states and South Australia) delayed their return to Standard Times by one week, because of the2006 Commonwealth Games held in Melbourne in March. DST ended on 2 April 2006.
There are situations in which a nationwide time is in effect. In the case of business activities, a national time can be used. For example, aprospectus for the issue of stock in a company would usually set the closing time for offers at some location (e.g. Sydney) as the time when offers must be received, regardless of the source of the offer. Similarly, tenders for their sale of stock usually set out the time at a given location by which they must be received to be considered. Another example is theAustralian Securities Exchange which operates on Sydney time.[31]
On the other hand, Federal legislation yields to state-regulated standard times in many diverse situations. For example, it yields in setting the normal working times of Federal employees, the recognition of public holidays, etc. The Federal government also relies on local times for Federal elections, so that the polls in Western Australia close two or three hours after those in the eastern states. Also, documents to be filed in aFederal Court may be filed based on the local time. The effect of this is that if there had been a failure to file a legal document on time in an eastern State, that document can sometimes still be filed (within two hours) in Western Australia.
The 18 zones for Australia as given byzone.tab of theIANA time zone database. Columns marked * are from the zone.tab.
| c.c.* | coordinates* | TZ* | Comments* | UTC offset | DST | Map |
|---|---|---|---|---|---|---|
| NF | −2903+16758 | Pacific/Norfolk | +11:00 | +12:00 |  | |
| AU | −3133+15905 | Australia/Lord_Howe | Lord Howe Island | +10:30 | +11:00 |  |
| AU | −5430+15857 | Antarctica/Macquarie | Macquarie Island | +10:00 | +11:00 |  |
| AU | −3352+15113 | Australia/Sydney | New South Wales (most areas) | +10:00 | +11:00 |  |
| AU | Australia/Canberra | +10:00 | +11:00 | Redirects to Australia/Sydney. | ||
| AU | −4253+14719 | Australia/Hobart | Tasmania | +10:00 | +11:00 |  |
| AU | Australia/Currie | +10:00 | +11:00 | Redirects to Australia/Hobart. | ||
| AU | Australia/Tasmania | +10:00 | +11:00 | Redirects to Australia/Hobart. | ||
| AU | −3749+14458 | Australia/Melbourne | Victoria | +10:00 | +11:00 |  |
| AU | Australia/Victoria | +10:00 | +11:00 | Redirects to Australia/Melbourne. | ||
| AU | −2728+15302 | Australia/Brisbane | Queensland (most areas) | +10:00 | +10:00 |  |
| AU | Australia/Queensland | +10:00 | +10:00 | Redirects to Australia/Brisbane. | ||
| AU | −2016+14900 | Australia/Lindeman | Queensland (Whitsunday Islands) | +10:00 | +10:00 |  |
| AU | −3157+14127 | Australia/Broken_Hill | New South Wales (Yancowinna) | +09:30 | +10:30 |  |
| AU | Australia/Yancowinna | +09:30 | +10:30 | Redirects to Australia/Broken_Hill. | ||
| AU | −3455+13835 | Australia/Adelaide | South Australia | +09:30 | +10:30 |  |
| AU | Australia/South | +09:30 | +10:30 | Redirects to Australia/Adelaide. | ||
| AU | −1228+13050 | Australia/Darwin | Northern Territory | +09:30 | +09:30 |  |
| AU | Australia/North | +09:30 | +09:30 | Redirects to Australia/Darwin. | ||
| AU | −3143+12852 | Australia/Eucla | Western Australia (Eucla) | +08:45 | +08:45 |  |
| AU | −3157+11551 | Australia/Perth | Western Australia (most areas) | +08:00 | +08:00 |  |
| AU | Australia/West | +08:00 | +08:00 | Redirects to Australia/Perth. | ||
| AQ | −6617+11031 | Antarctica/Casey | Casey | +08:00 | +08:00 |  |
| TH | +1345+10031 | Asia/Bangkok | north Vietnam | +07:00 | +07:00 |  |
| CX | −1025+10543 | Indian/Christmas | +07:00 | +07:00 | Redirects to Asia/Bangkok. | |
| AQ | −6835+07758 | Antarctica/Davis | Davis | +07:00 | +07:00 |  |
| MM | +1647+09610 | Asia/Yangon | +06:30 | +06:30 |  | |
| CC | −1210+09655 | Indian/Cocos | +06:30 | +06:30 | Redirects to Asia/Yangon. | |
| AQ | −6736+06253 | Antarctica/Mawson | Mawson | +05:00 | +05:00 |  |
| MV | +0410+07330 | Indian/Maldives | Kerguelen, St Paul I, Amsterdam I | +05:00 | +05:00 |  |
Queensland has had a particularly involved debate over daylight saving time, with public opinion geographically divided. The state's first trial of DST lasted one year, from 31 October 1971 to 27 February 1972.[32] In 1973 the Committee on Daylight Saving analysed this trial and the effects of daylight saving on different demographics, and ultimately concluded not to adopt daylight saving time. The committee's reasons include Queensland's unsuitable geography and a lack of broad support from denizens.[33]
Later, another introduction of DST was trialled from 29 October 1989 to 4 March 1990, overseen by the daylight saving task force. At the task force's recommendation, the trial was extended from one to three years.[34] The Legislative Assembly voted to hold areferendum on DST at the trial's conclusion in 1992, which was defeated with a 54.5 per cent negative vote.[34] The referendum result displayed a distinct trend—that public opinion on DST in Queensland is geographically divided, with the negative vote being strongest in northern and western districts, while the positive vote being strongest in the southeastern region (e.g. inBrisbane).[33] The holiday islands in the Whitsundays (Hayman,Lindeman andHamilton) continued to observe DST in defiance of the Standard Time Act (The "Australia/Lindeman" Timezone in the tz database is based on this). However the practice was abandoned two years later in 1995. Heron Island, 72 km off the coast off Gladstone, has two time zones: the resort follows DST all year round, whereas "the Marine Research Centre and the Parks and Wildlife office on the island remain on Eastern Standard Time".
Since the late 1900s, there have been a number of petitions submitted to theLegislative Assembly of Queensland, lobbying for the introduction of daylight saving time or for another referendum to be held. A petition in 2006 was signed by 62,232 people. In response to these petitions, then Queensland PremierPeter Beattie commissioned research to find out if it should be re-introduced into Queensland. Around this time, Beattie predicted that daylight saving in Queensland would increase the rate ofskin cancer in the state, an assertion for which there is no evidence, according to the Queensland Cancer Fund.[35]
In October 2007, the government-commissioned research was presented toAnna Bligh, who had replaced Peter Beattie as thePremier of Queensland; she ruled out holding a new referendum, despite the report indicating that 59 per cent of the residents of Queensland and 69 per cent of those in southeastern Queensland to be in favour of adopting daylight saving.[36]
In December 2008, theDaylight Saving for South East Queensland (DS4SEQ) political party was officially registered, to advocate for the use of a two-time-zone system for DST in Queensland, with most of the state (in land area) using standard time. This party contested theMarch 2009 Queensland State election with 32 candidates, and it received about one per cent of the statewide primary vote.[37]
In early 2010, the DS4SEQpolitical party approached theindependent member,Peter Wellington, to introduce a private member's bill for DST.[38]Since Wellington agreed with the principles of the DS4SEQ proposal, specifically the dual-time-zone system, he drafted theDaylight Saving for South East Queensland Referendum Bill 2010 and he submitted this bill toQueensland Parliament on 14 April 2010.[39] Wellington called for a referendum to be held at the next state election on the introduction of DST into southeastern Queensland under the dual-time-zone system.
In response to this bill, Premier Anna Bligh announced a community consultation process, which resulted in over 74,000 respondents participating, 64 per cent of whom voted in favour of a trial, and 63 per cent of whom were in favour of holding a referendum.[40] The decision announced by the Premier on 7 June 2010 was that her Government would not support the bill because rural Queenslanders were overwhelmingly opposed to DST.[41] The Bill was defeated in Queensland Parliament on 15 June 2011.[42]
Western Australia has also had a particularly involved debate over DST, with the issue being put to a referendum four times: in 1975, 1984, 1992, and 2009. All of these proposals to adopt DST were defeated. Voters registered a negative vote of 54.6 per cent in the2009 referendum, the highest percentage for all four of these referendums. Each referendum followed a trial period during which the state observed DST. The first three followed a one-year trial, while the 2006Western Australian Daylight Saving Bill (No. 2) 2006 instituted a trial of DST beginning on 3 December 2006, and lasting for three years.
Some towns located near the border of another state or territory use a different time zone to the rest of their own state or territory and may follow the bordering state or territory's time zone instead. The most well-known example of this isBroken Hill and the surrounding area, which, despite being located in New South Wales, use the same time zone as South Australia year-round.
Additionally,Gold Coast Airport, which straddles the border between New South Wales and Queensland (with the majority of the airport on theGold Coast and a small portion of it inTweed Heads), usesAustralian Eastern Standard Time (AEST) throughout the airport all year round, despite New South Wales observingdaylight savings (which Queensland does not observe).
To simplify the matter, Arubbidy Station — located between Balladonia and Eucla — operates off its own time, distinct to Eucla time, according to owner Matthew Lewis. "If you go through Caiguna, [the sign] says move your clocks back 45 minutes. We say we're not that smart really so we just go with one hour, so we're one hour on from WA," he said.
On its four-day journey across this Continent/Country, somewhere in the middle of the Nullarbor Plain, the Indian pacific train creates its own time zone for scheduling purposes.
Tomorrow we would switch our clocks to "Train Time", ninety minutes behind Adelaide. This unofficial time zone was needed because Australia's states were huge, and their time zones were synchronised with their biggest population centers.
