AEST — Australian Eastern Standard Time

Australian Eastern Standard Time (AEST) is ten hours ahead of Coordinated Universal Time and is used by the eastern Australian states of New South Wales, Victoria, Queensland, Tasmania, and the Australian Capital Territory. Sydney and Melbourne, Australia's two largest cities, both operate on AEST, making it the most widely used time zone in Australia by population.

Australia uses three standard time zones across its continental territory: Western (UTC+8), Central (UTC+9:30), and Eastern (UTC+10). The eastern time zone covers the most economically significant and densely populated part of the country, including the financial capital of Sydney, the cultural capital of Melbourne, the political capital of Canberra, and the tourism hub of the Gold Coast. Queensland's decision not to observe DST has been a perennial political issue, with multiple referendums on the subject failing.

During daylight saving time, New South Wales, Victoria, Tasmania, and the ACT switch to Australian Eastern Daylight Time (AEDT, UTC+11) from the first Sunday in October to the first Sunday in April. However, Queensland does not observe DST, creating a one-hour time difference between Sydney and Brisbane during the summer months. This split has practical implications for business, travel, and television scheduling along the state border.