How daylight saving affects your sleep and what you can do about it 

The clock will move back an hour this weekend in most Australian states and territories as Daylight Saving Time (DST) comes to an end in the wee hours of Sunday 7 April. This means that at 3am the clock turns back to 2am.

Originally introduced in Germany back in 1916 to save energy during the First World War, the practice of setting the clock an hour ahead in spring and an hour back in autumn has been adopted by about 70 countries worldwide.  

If you find the time change disorienting, you’re not alone. Aside from inconveniencing those of us with oven clocks, analogue watches and older cars, research has shown that the transitions in and out of daylight saving can also affect our bodies. 

“The clock going backward in April and going forward in October can have multiple health implications,” Dr Tergel Namsrai, a neuroscientist from The Australian National University, explains.  

While losing or gaining an hour of sleep may not seem like a big change, research has shown this small shift can be surprisingly disruptive. 

“Our internal clocks are regulated by a mix of light, hormones and sleep pressure – which is a biological process that urges us to sleep,” Namsrai says. 

The time change linked to daylight saving can mean that we are exposed to a different amount of light than usual, which in turn disrupts our normal sleep/wake cycle, known as our circadian rhythm. This can impact both how long we snooze for as well as the quality of that slumber, with research suggesting this disturbance can last for weeks following the transition.  

While stepping up your caffeine intake might seem like all you need to do to get through a few nights of inferior shuteye, that may not be the case.  

According to Namsrai, poor sleep quality and duration can be associated with decreased cognitive performance and increased risk of dementia. Circadian rhythm disruptions can also impact our cardiovascular health.  

An Australian study spanning 20 years found that the October time change, where the clock moves an hour forward, is linked to increased cardiac arrest rates. This health risk is one of the reasons the European Parliament voted to abolish DST in 2019 – although this change has yet to be implemented.  

As we gain an hour in this weekend’s transition, the impact is not so disruptive.

“Importantly, it’s an opportunity to improve your sleep habits by recommitting to a regular bedtime and waking hour,” Namsrai says.  

She also has advice to keep up your sleeve for the beginning of DST in October – a routine she uses with her own kids. 

“I adjust their sleep routines 10 minutes a day for two weeks, so that they will not lose an hour of sleep when the time moves forward.”