Australia spans three mainland timezone groups that do not all change clocks on the same schedule — making it one of the most complex countries to schedule across.
Australian Eastern Standard Time (AEST, UTC+10:00) covers Queensland, New South Wales, Victoria, Tasmania, and the ACT. However, Queensland does not observe daylight saving time. When NSW and Victoria switch to AEDT (UTC+11:00) in October, Brisbane stays on AEST — one hour behind Sydney and Melbourne for roughly seven months of the year.
Australian Central Standard Time (ACST, UTC+9:30) covers South Australia and the Northern Territory. South Australia observes ACDT (UTC+10:30) in summer; the Northern Territory stays on ACST year-round with no clock change.
Australian Western Standard Time (AWST, UTC+8:00) covers Western Australia. Perth does not observe daylight saving time, placing it 2 hours behind Sydney in winter and 3 hours behind during the AEDT period.
DST in 2025: clocks in NSW, VIC, SA, TAS, and ACT go forward one hour on Sunday 5 October 2025, and fall back on Sunday 6 April 2025. Queensland, Western Australia, and the Northern Territory make no change.
Inter-city time gaps (during AEDT period, approximately October–April): Sydney and Melbourne are on the same time. Brisbane is 1 hour behind Sydney. Adelaide is 30 minutes behind Sydney. Perth is 3 hours behind Sydney. During the AEST period (May–September) the Sydney–Brisbane gap closes, and Sydney–Perth narrows to 2 hours.