Residents in the ACT, Victoria, New South Wales, Tasmania and South Australia will lose an hour's sleep on Sunday, as clocks reset at 2am.

Smartphones should automatically reset to the correct time.

Clocks were first wound forward during World War I and II, and later adopted again in Tasmania in 1967. NSW, Victoria, Queensland, South Australia and the ACT followed suit in 1971, although Queenslanders discontinued the practice the following year.

Daylight saving time will end on Sunday, April 2.