Daylight Saving Time is used in New South Wales, the Australian Capital Territory, Victoria, South Australia and Tasmania from the beginning of October through to the beginning of April.
Northern Territory, Western Australia and Queensland do not use DST.
Australia is divided into 6 states: New South Wales, Victoria, Queensland, South Australia, Western Australia and Tasmania and 2 territories; the Australian Capital Territory and the Northern Territory.
There are three time zones in Australia:
Eastern Standard Time (EST): in New South Wales, Australian Capital Territory, Victoria, Tasmania and Queensland.
Central Standard Time (CST) in South Australia and Northern Territory.
Western Standard Time (WST) in Western Australia.
Australian states except have daylight saving during the summer months.
Official source: The National Standards Commission (Commonwealth statutory authority established in 1950 and operating under the National Measurement Act 1960)
The Commission is responsible for advising the Government on the scientific, technical and legislative requirements of Australia's national measurement system, and has specific responsibilities for coordinating the national measurement system, ensuring that trade measurement instruments comply with international and national legal metrology standards, and for the completion of metrication.