Time in Australia

Time in Australia is calculated using standard time, with three zones: Australian Western Standard Time (AWST), Australian Central Standard Time (ACST), and Australian Eastern Standard Time (AEST). The three zones use three standard UTC offsets: western (UTC+08:00), central (UTC+09:30) and eastern (UTC+10:00). Time is regulated by state governments, and within the three standard time zones daylight saving time (DST) differs between the jurisdiction. Australia's external territories observe different time zones.

Standard time was introduced in the 1890s when all of the Dominions adopted it. Before the switch to standard times, each local city or town was free to determine its local time, called local mean time. Now, Western Australia uses Western Standard Time; South Australia and the Northern Territory use Central Standard Time; while New South Wales, Queensland, Tasmania, Victoria, and the Australian Capital Territory (ACT) use Eastern Standard Time.

DST is used in South Australia, New South Wales, Victoria, Tasmania, and the ACT. It is not used in Western Australia, Queensland, or in the Northern Territory.