There are three time zones within the Australian continent. The eastern states - Queensland, New South Wales, Tasmania and Victoria - are 30 minutes ahead of South Australia and the Northern Territory (Broken Hill, in the far west of New South Wales is included in this zone) and two hours ahead of Western Australia.
Australia is just to the west of the International Date Line. From the end of October to end of March daylight saving applies (clocks are advanced by one hour).
New South Wales, Victoria and Tasmania follow Eastern Summer Time, Queensland has not adopted this practice. South Australia follows Summer Time, as does the Northern Territory. This period usually falls between November and February but can extend for up to two weeks on either side. Tasmania has extended daylight saving to six months from early October to late March.