Sleep experts debunk daylight saving health risks

Nyk Carnsew |

Clocks across southeastern Australia will spring forward one hour from 2am.
Clocks across southeastern Australia will spring forward one hour from 2am.

Daylight saving has no negative impact on people’s health, a world-first study has found as southeastern Australia prepares to roll the clocks forward.

The effect of daylight saving on health has long been the subject of speculation, amid concerns over loss of sleep as well as the increased risk of strokes and heart attacks.

Sleep experts from Flinders University in Adelaide have carried out the world’s first comprehensive study into the practice’s long-term impact and found no significant evidence it results in a loss of sleep.

Sleepy people (file image)
The impact of potential sleep loss at the start of daylight saving is minimal, researchers say. (Joe Castro/AAP PHOTOS)

Researcher Reece Kemp says people living in daylight saving states get comparable sleep to those who don’t, aside from a small tendency to go to bed and wake up later.

“We got the opportunity to study a lot of downstream effects in sleep health and daytime functioning … once again we found really no difference,” Mr Kemp told AAP.

The researchers focused on the later months of daylight savings time, as prior studies only focused on the impact during the first few weeks. 

“If you’re going to be removing daylight savings time you want to know what the exact cost of it is,” Mr Kemp said.

“The interesting opportunity about Australia is that you have basically a half-split of states that observe daylight saving time and those who are on standard time.” 

The researchers compared the sleep patterns of people in states that observe daylight saving against those that don’t, using data from two nationwide questionnaires.

A kayaker paddles at sunrise in Sydney (file image)
People in daylight saving states are urged to stick to routines during the time change. (Mick Tsikas/AAP PHOTOS)

While the evidence does suggest people could lose sleep in the first few weeks, the impact was no worse than jet lag, Mr Kemp said.

The tendency of Australians in states that observe daylight saving to go to bed and wake up later also likely offsets any long-term risk.

“Is that potentially people in daylight savings time are adapting? Possibly,” he said.

However, people concerned about adjusting to the transition can avoid losing sleep by sticking to a strict sleep schedule over the weekend and avoiding staying up late or sleeping in.

“Because of the clock change, you might be waking up quite later by body clock time and thus you might not be feeling super sleepy on that Sunday night,” Mr Kemp said.

“That’s where a lot of this idea that daylight savings time was harmful came from.

“Come Monday morning, you might be feeling really tired and that would compound throughout the work week and result in an even bigger sleep the next weekend.”

Daylight saving time begins on Sunday at 2am AEST, when clocks move forward one hour to 3am AEDT in all states and territories except Queensland, Western Australia and the Northern Territory.

AAP