Is daylight saving bad for your health?

NSW, Victoria, Tasmania, South Australia and the ACT are all due to turn back the clocks by one hour at 3am on Sunday.

While some studies have linked the time shift to an increase in heart attacks and traffic accidents in the days that follow, sleep expert Professor Ron Grunstein, of the University of Sydney, says suggestions that the time change is harmful are largely a myth.

Daylight saving disrupts the body's circadian rhythms, a system of "clocks" that affect a multitude of biological processes in the body.

Disrupting these rhythms, in some cases, can have adverse impacts on individual's health and safety, Prof Grunstein says.

"Anything that puts out the body's rhythm is going to result in some symptoms and in a chronic situation, ill health," he told AAP.

But he says the time change, for most people, won't result in serious health issues.

"I don't think there's strong evidence for the transition phase being associated with lots of bad things," he said.

"During daylight savings people's activity increases, so from that public health perspective, it's seen as a positive.

"Though I think someone found in the week following daylight savings time there are more medical appointments booked because people forget."

While many are looking forward to Sunday's sleep-in Dr Svetlana Postnova, from the University of Sydney, says the thrill is fleeting because studies have shown it doesn't actually translate to extra sleep in the days that follow.

So whether you're turning the clock back or forward you'll still feel the negative effects of "circadian misalignment", a feeling likened to jet lag.

Dr Postnova says it can take a week or longer for the body to adapt to the change, but in some circumstances, people don't adapt at all.

"When we are on standard time our sleep follows dawn, which is not the case during daylight savings time ... it sees that standard time is more aligned with our biology," she said.

"What consequences it may have on our health and performance is still unclear."

Australian Associated Press