How does daylight saving time affect sleep and mental health?

Photo by Alyssa Stone/Northeastern University

On Sunday, Nov. 5, parts of the world, including most of the United States and Canada, will participate in the annual ritual of setting their clocks an hour back to mark the end of daylight saving time. 

Daylight saving time extends the day during the warmer months, and then sunset comes an hour earlier when the clocks are changed back in the fall. 

headshot of Kristen Lee
Northeastern teaching professor Kristen Lee. Photo by Alyssa Stone/Northeastern University

However, some question its effect on sleep and mental health and argue that it should be discontinued. Some research suggests daylight saving causes an increase in traffic accidents and workplace injuries, and that it no longer saves energy — the original goal when it was implemented in 1918.

The Senate responded to the debate last March with passage of the Sunshine Protection Act, a bill that would have made daylight saving time permanent. However, the bill did not pass the House. 

Should we do away with daylight saving time? Northeastern teaching professor Kristen Lee talked to Northeastern Global News about the impact of daylight saving on sleep and mental health, whether the bill would help or hurt, and how daylight saving can help us reflect on our own routines. An expert in behavioral health and resilience, Lee’s comments have been edited for brevity and clarity. 

How does daylight saving time affect sleep and mental health?

Sleep is such a critical cornerstone of emotional regulation and maintaining solid mental health. So any type of disruption can be really corrosive. It can be really difficult to contend with, particularly when it involves reduction in available light. 

With seasonal affect disorder, many people struggle during the winter months with the cold and the lack of light, and to that end it’s really important that we look to the kinds of things that can maximize our emotional regulation and help make up for the loss of light and the changes in our sleep schedule.

What’s going on in our bodies during this time that we may not be aware of?

What the research shows is that trying to get up and go to bed every day at the same time is beneficial, and we know when we’re dealing with sleep disruptions or irregularity, it can throw us off. It can leave us in a state of difficulty focusing, it can affect our mood, and just leave us more susceptible to reactivity.

How can people take care of themselves during this time?

One thing is to focus on our locus of control. I think it’s jarring or disappointing for people who were looking forward to [not having daylight saving anymore]. I think it’s important to focus on whatever we can do to make consistency in our sleep and wellbeing protocol—getting up and going to bed, as consistently as possible, at the same time. 

The other thing is that natural light is really important. There’s a lot of studies that show the important effects of natural light, green space and getting away from our screen can really be helpful. That can really give us that extra measure of calibration in our brains and bodies rather than just being inside in the dark or on screens excessively.

Does sleep inconsistency impact some people more than others?

Amongst high-achieving people and within their communities, leisure and rest are oftentimes stigmatized or they can be squeezed out with competing priorities. [It’s important to] give ourselves permission to engage in leisure and rest and try to make the time to get outside in the daylight to the extent that’s possible.

Everyone has different sensitivities to these shifts, so it’s important to think about what our own sensitivities are and then to try to figure out how to carve out time to just be out breathing the air, being in natural light, and set up a sleep schedule that works well for us. I think it’s hard for students and professionals in particular. For all of us, it’s hard to find the right amount of sleep. But so many studies are citing the value of the protective nature of sleep towards our wellbeing and mental health.

Do you support the bill that would make standard time permanent? 

I do. I think it would be beneficial to pass it. But I think the key thing is, irrespective of the bill passing, highlighting this conversation and this issue can help shed—no pun intended—some important light on sleep and sleep quality and sleep consistency. 

I think that’s a key thing, too—that it can raise awareness for people to be more mindful. And it’s so difficult, given technology, given the hyper-competitive market, the demands we all have. But I think this topic can help people recalibrate themselves and realize how vital that sleep consistency is.

It raises our attention toward how sleep impacts our wellbeing, how light, how green space, how time in nature, time away from screens, affects us. Sometimes we don’t realize because we’re so hyperfocused on our work and our priorities and so forth. And so I think this is a good inflection point. Irrespective of if this gets eliminated eventually, we all should take psychological agency to focus on the aspects of our sleep and rest and leisure protocol that we institute in our own lives.

What are some tips to help prioritize sleep more?

Setting boundaries around how much we say yes to, I think that can be a major issue. If we take on too much, it can squeeze out our time for sleep. Another thing is working to get good exercise. A lot of studies show that morning exercise in particular is a really helpful thing, especially if it’s outdoors. 

The other thing is trying to reduce excessive use of social media and screen time. Of course there’s been a lot of attention around getting off screens at least a minimum of an hour before bedtime as a way to ensure better sleep. Some people are also recommending not sleeping in the same room with your phone and not going to bed on the phone or waking up on the phone, giving the brain that time to be mindful, to recalibrate.