Columns, Opinions

Mulligan ’19: The cost of daylight saving

Staff Columnist
Sunday, November 12, 2017

Every year in November, I hear people complain about the end of Daylight Saving Time, and I understand why. In New England especially, the sudden earliness of sunsets can be a shock. To paraphrase a classmate of mine, the dark has a way of making you feel as though you should put on your pajamas and get into bed — an unproductive action when it is only 6 p.m. and you still have piles of homework to attack.

While the changing of the clocks can be little more than an annoyance for some, for others it affects health detrimentally. Businesses are the primary benefactors of DST. Opposing DST should be part of the larger social justice movement that aims to put people’s physical and mental wellbeing over corporate profitability.

DST began as a temporary measure to conserve energy during World War I, and was reintroduced for the same reasons during World War II. Following the end of the war, while no longer observed nationally, cities and counties continued to set their own policies regarding the time change. The Uniform Time Act of 1966 reserved the power to opt in or out of DST for states alone. It also ensured that all states who took part moved their clocks at the same time. The most recent update to the act came with the Energy Policy Act of 2005, which led to the majority of the United States observing DST for eight months of the year.

Though DST was created to conserve energy, recent research suggests that it doesn’t. The Department of Energy found in 2008 that DST lowered yearly energy consumption by one-third of a percent. But multiple other studies found no energy savings, and one study even pointed to energy use increasing during DST by up to 1 percent.

Given that DST has a negligible effect on energy conservation, it is clear that  it is most advantageous for people who benefit financially from it.

Turns out, more hours of sunlight very clearly encourages consumption. People are more inclined to go out and spend during the daytime. Convenience stores, golf courses and retailers of outdoor activities equipment have all lobbied in support of DST. In 2010, the then-chairman of the Association for Convenience and Fuel Retailing estimated that convenience stores pocketed an additional $1 billion a year since DST was lengthened in 1986.

But any monetary benefit comes at a cost to our wellbeing. While 2007 research associated DST with a reduced number of traffic accidents, a more recent study from the University of Colorado found the opposite, linking DST to a higher rate of fatal accidents. The first days after DST goes into effect each year show increased rates of strokes and heart attacks. And having time springing forward and falling back impacts circadian rhythms, upsetting sleep cycles.

Its toll on mental health is also just as serious. A study published in Epidemiology in May 2017 found an 11 percent increase in diagnoses of unipolar depression in the first two months after DST ends. Although more work is needed to determine the reasons for that association, the researchers proposed that it is linked to the “psychological distress” of the sun suddenly setting an hour earlier. Their work was praised by Norman Rosenthal, the first researcher to diagnose and treat seasonal affective disorder, a condition in which people experience depression at a particular point in the year, often coinciding with the shortening winter days.

DST is exactly the sort of cause that should attract people’s attention; it is emblematic of a society where lobbyists encourage the government to put profits ahead of health. It’s time to focus on what research says about DST’s negative impacts to human physiology, rather than on corporate interests.

Caroline Mulligan ’19 can be reached at Please send responses to this opinion to and other op-eds to