Daylight Saving and Sleep

This is a fact sheet about Daylight Saving and Sleep. DST can have an impact on sleep patterns & overall well-being. It can disrupt the body's internal circadian rhythm and sleep-wake cycle.

Sunrise over the city. Photo by Pixabay
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January 12, 2024
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MIN READ

Summary

Things you should know:

  • Daylight Saving Time is only observed in NSW, Victoria, South Australia, and the ACT.
  • At the beginning of Spring, the clocks are moved forward one hour, and in Autumn the clocks are moved back one hour.
  • Moving the clocks forward can increase the risk of sleep loss and drowsiness.
  • There are strategies to help adjust to Daylight Saving Time and reduce the risk of sleep loss.

Daylight saving time in Australia

In Australia, daylight saving is observed in NewSouth Wales, Victoria, South Australia, Tasmania, and the Australian Capital Territory. Daylight saving is not observed in Queensland, the Northern Territory or Western Australia.

Daylight Saving Time begins at 2am on the first Sunday in October, when clocks are put forward one hour. It ends at 2am (which is 3am Daylight Saving Time) on the first Sunday in April, when clocks are putback one hour.

Moving the clocks forward and sleep 

The clocks are set one hour forward in Spring (October), this is often referred to as ‘spring forward’ to help us remember to turn our clocks forward. Although we “gain” an extra hour of daylight, we also lose an hour of sleep if we are not prepared.

Moving our clocks can disrupt our sleep patterns. In general, "losing" an hour in the Spring is more difficult to adjust to than "gaining" an hour in the Autumn when we move the clocks back one hour.  Our internal body clock or 24-hour circadian rhythm (see Body Clock) will have to adjust to the time shift. Although most people will do this without any problem, we do need to be aware that there is an increased chance of sleepiness while the body adjusts to the new timeframe.

Our circadian rhythms are timed to match the environmental cycle of light and darkness. Daylight saving throws our circadian rhythms out of sync because we are suddenly required to wake at a time when the body clock is still programmed for sleep. However, if you adjust your bedtime earlier for 3 or 4 nights before the Spring daylight savings transition, you will reduce the risk of sleep loss, and be less susceptible to sleepiness the following day.

Moving the clocks back and sleep

At the end of daylight saving in Autumn (April), the clocks will be put back one hour, meaning we will enjoy an extra hour in our “night”. The term ‘fall back’ is used in many countries so we remember to turn our clocks back one hour.

Thanks to that extra hour, "falling back" isn't nearly as disruptive to our bodies as putting the clocks forward at the beginning of daylight saving. The body’s circadian rhythm, our built-in timeclock, operates on a slightly longer than 24-hour cycle (see Body Clock). This means that being able to extend our day, through going to bed a bit later in the evening, is much easier than it is to shorten our day.

While it can take up to a week to feel back to normal after the beginning of Daylight Saving Time in October, in April it usually only takes one night.

Falling back may even help us to sleep better. After the time change, it will get dark earlier, which could prompt us to go to bed earlier, especially after the long, well-lit summer evenings that encourages us to stay up much later. It will be lighter in the mornings, making it easier to get up to do some exercise to start the day well.

How important is sleeping well?

It is reported that people can lose up to one hour of sleep when the clocks are moved forward in October. Although an hour less of sleep may not seem like a big deal, this amount of sleep loss can affect our performance the next day. For example, we may not be as alert as normal during the day, especially at the start and end of the day. Sleep disruptions that affect our alertness levels may increase the risk of motor vehicle and workplace accidents. For this reason, if people are driving, using heavy machinery or in situations where safety is an issue, they need to be extra vigilant in the lead up to, and after, daylight saving.  

People who already struggle with getting enough sleep, such as those with a sleep disorder (e.g., insomniasleep apnoea) and shift workers, may find it more difficult to adjust to day light saving time in the Spring. Children can also take longer than adults to adjust to daylight saving as they find it harder to understand the concept of time change, and for younger children it can still be light when they go to bed.

Strategies to help you adjust to Daylight Saving Time

The Sleep Health Foundation has developed the below list of tips to help people prepare and adjust to daylight saving time:

  • Make the bedroom as bright as possible when you first wake up in the morning.
  • Eat a good breakfast.
  • Go outside in the sunlight in the early mornings.
  • Exercise outside in the mornings.
  • Try to get between seven to nine hours sleep each night.
  • Don’t exercise just before going to bed.
  • Don’t drink coffee, tea or other caffeine drinks in the evening, avoid smoking just before bed or during the night.
  • Don’t go to bed hungry or too soon after eating a large meal.

In Spring:

  • Go to bed 15 -20 minutes earlier for 3 to 4 days before putting the clocks forward.
  • Set your alarm 30 minutes earlier on Saturday and Sunday mornings in preparation for the early start on Monday.

Where can I find out more information?

https://www.govt.nz/browse/recreation-and-the-environment/daylight-saving/

What do you think of Daylight Saving Time?

As part of its work, the Sleep Health Foundation is now seeking the views of the Australian public on the impacts of daylight saving.  “Whether or not you live in an area that has daylight saving, we are interested in your perspectives.  There have been referenda about daylight saving in different states of Australia, but we really want to build an understanding across all regions of Australia” says Dr Junge.

Complete the survey here.

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