Come Sunday evening most Australians will be basking in an extra hour of sunlight with daylight saving pushing the time forward one hour.

Most smartphone devices and computers automatically adjust the time but analogue clocks need to be changed manually.

Daylight saving always falls on the first Sunday of October.

It's still a contentious issue for some states with Queensland, the Northern Territory and Western Australia not taking part.

Daylight saving means Australia's three standard time zones split into five, while Western Australia falls three hours behind those states that observe DST.

Sleep experts warn people to pay attention to their drowsiness levels immediately after the time change.

"The first 24 hours after the clock changes there can be an increase in accidents," Dr Moira Junge from the Sleep Health Foundation told AAP.

"Don't over-think it too much, while there is a shift in our body clock, it's only for a short period of time."

Daylight saving finishes in April next year when the clocks wind back an hour from 3am.