There are three time zones in Australia spread over the width of Australia from Sydney to Perth and totaling 2hrs in difference, except for daylight saving time:
Eastern Standard Time (EST) - which includes New South Wales, Victoria, Queensland, Tasmania and the Australian Capital Territory
Central Standard Time (CST) - which includes South Australia and the Northern Territory
Western Standard Time (WST) - Western Australia.
CST is one half hour behind EST, while WST is two hours behind EST
