There are a lot of things to love about spring: warmer temperatures, new leaves on the trees, the days getting longer. But one thing that’s not so great is the switch to daylight saving time (DST), when the clocks spring forward and we all lose an hour of sleep.
Losing an hour of sleep may not sound like much. Parents of young kids get that — or more — most nights, and many of us indulge in an extra hour of late-night TV or socializing on the weekends, resulting in a later bedtime. But one hour of sleep loss impacts everything from health to productivity to public safety. And the local time change in March is more than just less sleep. Our whole schedule and daylight time is shifted an hour later, having a huge impact on our bodies and brains.
In this article, we’ll show you how you can prepare for daylight saving time, so you can minimize the negative effects that come with the shift.
It’s easy to think the only way the change to DST impacts our sleep is by making it shorter. But when the new time comes into effect, we’re more likely to have trouble falling and staying asleep, and can experience sleep loss for a week after the change. It can even take four or more weeks for our bodies to adjust to the earlier schedule.
Standard time starts on the first Sunday of November — or the last Sunday of October in much of Europe. Here, we get an extra hour in bed, but studies show we don’t actually sleep longer on that night, and we get less sleep than usual over the next week.
In spring, when you wake up an hour earlier than usual — and go about your day eating, working, and exercising an hour earlier than usual — your body experiences a kind of jet lag. Suddenly, you're not living in sync with your circadian rhythm, or the internal clock that dictates our energy levels over a roughly 24-hour cycle.
Among other things, your circadian rhythm controls when your body feels awake and when it feels sleepy. So when we’re not living in sync with it, it can be harder to fall asleep when we want to, leaving us awake in bed at night, and we may not have energy when we want to — think grogginess during an important 10 a.m. meeting.
This circadian misalignment also leads to sleep debt, the amount of sleep you “owe” your body over the last 14 nights when compared to your sleep need.
Your sleep need is the genetically determined amount of sleep your body needs. The average sleep need is 8 hours 10 minutes, plus or minus 44 minutes or so, but 13.5% of the population may need 9 hours or more sleep a night.
Sleep debt is one of the biggest factors determining how you feel and perform each day. So the RISE app focuses on this number, helping you calculate and keep track of it as you pay it back. We recommend keeping sleep debt below five hours to feel and function your best each day.
So we’ve established DST is more than just an hour of sleep loss. It throws off our circadian rhythms and increases the likelihood of sleep debt for days or weeks to come. And it takes a while to adjust to the new schedule, too. Even more disturbing, circadian misalignment has been linked to everything from impaired cognition to cancer.
One study found a one-hour shift in sleep times — either because of DST or even just sleeping in on the weekends — significantly slowed reaction times. And other studies have found the rate of workplace injuries, traffic accidents, and even heart attacks and strokes increases in the days following the shift to DST.
When the clocks spring forward in March, it feels like a much harder transition than when the clocks go back in November. But, surprisingly, that’s not just because we physically lose an hour in bed.
When standard time ends, we get an extra hour of daylight in the evenings, but darker mornings. This messes with our natural circadian rhythm, which needs light first thing to regulate properly. Morning light triggers our brains into releasing cortisol, norepinephrine, and serotonin, which make us feel awake and alert.
When we’re waking up and spending the first hour or more of our day in darkness, these processes aren’t as efficient and our circadian rhythm is misaligned from the moment we wake up. This can lead to feeling groggy in the day and potentially wired come the time we want to sleep — not to mention simply not operating at our full potential.
Everyone reacts to the shift in schedule differently, and it largely comes down to your chronotype — whether you’re an early bird, night owl, or somewhere in between. Your chronotype explains your natural tendency to wake up and go to sleep earlier or later in the day.
Most people, except for extreme early birds, adjust more easily to a delay in the time than an advance. So most of us respond better to jet lag after flying west than east, and to coming out of DST than going into it.
There is some evidence to show that early birds find the spring time change easier than night owls, but it still affects us all. Even early birds may experience circadian misalignment and an increase in sleep debt following the schedule change. Some of us may experience sleep loss for eight weeks, and there’s evidence some extreme night owls never fully adjust to the time change!
When it comes to the fall time change, however, there’s not as much of a difference — though there is some evidence to show it’s harder on early birds due to the lack of morning light.
So now we know just how disruptive DST can be, what can we do about it?
Go in Low
Losing an hour of sleep is difficult for anyone, but it’s especially difficult for those who are already sleep deprived. Those who haven’t been meeting their sleep need have been found to have a harder time adjusting to the time change. To prepare, keep your sleep debt low, especially around the shift in and out of DST.
Ease in Gradually
Instead of jumping forward a whole hour on the second Sunday in March, ease yourself in by slowly adjusting your schedule. About one week before, start moving your sleep and wake times 15 minutes later each day.
Prioritize Sleep Hygiene
As we’ve seen, it’s not just one hour of sleep loss, it’s days — or sometimes weeks — of disturbed sleep. To minimize this, focus on practicing good sleep hygiene.
Sleep hygiene is a set of behaviors you can do each day to help you fall asleep faster and stay asleep through the night. These include keeping your bedroom dark and cool, winding down before bed, and avoiding things that’ll disturb sleep, like afternoon caffeinated beverages, alcohol, and large evening meals. RISE can tell you the ideal cut off time for these things based on your circadian rhythm.
Everything from total sleep time to sleep efficiency may be worse in the summer months, potentially due to factors like temperature, humidity, and sunlight. Here’s how you can keep on top of your sleep beyond the spring time change.
Think about Light
Light is one of the most powerful tools we have when it comes to adjusting our circadian rhythm, and getting natural daylight in the mornings is much easier in spring and summer time. Be sure to get at least ten minutes of light as soon as you can after waking up, ideally from the sun.
Come evening, dim the lights, put on blue-light blocking glasses, and avoid getting too much light exposure. Depending on where you live, this can be tricky if it’s still light out when you’re winding down for bed. To help, you can use an eye mask and blackout curtains to keep your bedroom dark.
Keep Things Cool
As well as spring and summer days being lighter, they’re also warmer. This is great in the mornings when you want to get outside and get natural light, but come nighttime, a warm bedroom isn’t ideal for sleep.
Ideally, you should keep your bedroom at a cool 65 to 68 degrees Fahrenheit for the best sleep. If you have air conditioning, you can set the temperature. If not, we shared tips on how to “hack” the best temperature for sleep.
DST began in Europe during World War I, and properly began in the US when congress passed the Uniform Time Act of 1966. You can find out more about the history of daylight saving time here.
But there’s more and more evidence showing the effects of daylight saving time go far beyond the one-hour time change. And we’re hit with this change twice a year.
Many countries don’t observe DST, including Iceland, Japan, and Costa Rica. In the US, places like Hawaii, Puerto Rico, Arizona — except for the Navajo Nation — don't either, as well as Guam, the US Virgin Islands, American Samoa, and the Northern Mariana Islands. Plus a 2019 poll found that 70% of Americans would prefer to do away with DST altogether — and these people may be in luck.
So far, 19 states have put forward legislation to remain in daylight saving time year round, ending the need for twice-yearly time changes. However, a change in federal law is required first to make this happen.
So until lawmakers make a change, we need to keep living with DST. But if the twice-yearly time change is good for one thing, it’s the reminder of just how important our sleep health is. There’s plenty of evidence showing how disruptive, dangerous and detrimental shifting our schedules by just one hour is — but that’s exactly what many of us do every week. Whether that’s sleeping in on the weekends or staying up late to get more work done, we regularly disrupt our circadian rhythms and don’t meet our sleep need.
To deal with DST, focus on keeping your sleep debt low, your sleep hygiene on point, and getting light in the morning and darkness in the evening. And this advice works for every other day of the year, too.
Not only does RISE calculate your sleep need and sleep debt for you, it helps you time sleep hygiene behaviors and predicts your circadian rhythm each day. This way, you can align your schedule with your natural energy cycle, allowing you to get the most out of each day, no matter the time.
RISE makes it easy to improve your sleep and daily energy to reach your potential
RISE makes it easy to improve your sleep and daily energy to reach your potential