Millions of Australians' clocks will be set forward an hour next month, 'losing' an hour of their day and maximising the time it stays bright in the evenings over spring and summer.
Around 80 per cent of Australians are in favour of the practice known as daylight saving, according to research from University of Queensland professor Thomas Sigler.
For many, the change is insignificant — people reported that they were glad to have another hour of sunlight in the evening.
But for some, the change rattles their body clock and can lead to negative health consequences.
University of Queensland researchers found daylight saving can create a 'social jetlag' because people are waking up with less sunlight and going to bed with more light.
In extreme circumstances, the effects can include inadequate sleep, decreased attention, increased metabolic and cardiovascular issues, mood disorders, and even a shortened lifespan.
Professor of neurology and pediatrics at Vanderbilt University Beth Marlow found moving the time forward an hour is much harder on the body than moving it backwards, and the effects can last all summer.
Writing in The Conversation, she said: "Exposure to light later into the evening delays the brain’s release of melatonin, the hormone that promotes drowsiness.
"This can interfere with sleep and cause us to sleep less overall, and the effect can last even after most people adjust to losing an hour of sleep at the start of daylight saving time."
When does daylight saving start in 2024?
Daylight saving starts at 2am on the first Sunday of October every year.
That means that this year, clocks will move forward by an hour at 2am on Sunday 6 October.
It ends at 2am standard time on the first Sunday of April, when clocks are put back an hour.
Where is daylight saving observed in Australia?
Daylight saving is observed in NSW, Victoria, South Australia, Tasmania, the ACT and Norfolk Island.
After daylight saving ends, Australia effectively loses two of its time zones.
It's up to individual states and territories to decide if they wish to observe it or not.
In 1916, Tasmania became the first Australian jurisdiction to introduce daylight saving, in a bid to save energy during World War One.
The rest of the country followed a year later, before it was scrapped in 1918.
Daylight saving was temporarily reintroduced across Australia during World War Two, between 1942 and 1944.
It was brought in again in Tasmania in 1967, with Victoria, NSW, SA, the ACT, and Queensland following in 1971 — but it only lasted in the Sunshine State until 1972.
