Written by Connor Zahler:
Daylight savings time may be no more. Or, rather, it may now continue forever. Recently, the U.S. Senate unanimously approved a bill that would make daylight savings time permanent. If passed by the House of Representatives and the President, we would spring forward in March 2023 and then not fall backward in the following November. Many have greeted this with glee; the dreaded lost hour from springing forward is no more! Others, including sleep experts, are a bit more hesitant, but why? Despite this seeming to be common-sense, the data behind daylight savings is actually very nuanced. Before discussing the pros and cons of each option, we should determine what Americans actually say they want.
There is broad support for no longer changing clocks, but there’s more nuance as to whether we should be on permanent standard time or permanent daylight savings time. In 2019, an AP-NORC poll found that about 70% of Americans would like to end the twice-a-year switch. Within the 70%, 40% supported standard time, while 30% supported daylight savings time. In short, a majority support ending our current system, but only 30% of Americans support the specific proposal at hand. Beside public opinion, there are other reasons to support ending the flip.
Switching times twice a year is associated with more car accidents and more heart attacks. 2019 research from the University of Colorado Boulder found that springing forward may increase fatal car accident risk by 6%, which translates to about 28 deaths a year. This increase is most pronounced in the morning and in the Western part of the U.S. Research from our own Michigan Medicine has shown that the incidence of heart attacks increases by 24% the Monday following a spring forward. However, this is partly counterbalanced by a 21% reduction the Tuesday after a fall back, suggesting that daylight savings time alters the timing, but not overall incidence, of heart attacks. In any case, the status quo presents avoidable risks that the Senate Bill proposes to fix.
The most major advocate for permanent standard time is the American Association of Sleep Medicine. Their 2020 position statement lays out why: standard time, they claim, is more in-line with our natural circadian rhythms. While a twice-yearly switch causes a major disruption, permanent daylight savings time would also cause an imbalance due to getting more light later in the day. Such an imbalance may increase our risk for obesity, metabolism disorders, and cardiovascular issues. They also point out that in the 1970s, when the U.S. temporarily instituted permanent daylight savings, there was an increase in morning fatalities for school-aged children between January and April (possibly linked to more darkness in the early morning).
Permanent daylight savings time has its own benefits, but these are murky and may not be backed by research. The main draws for daylight savings are an alleged economic boost and decrease in time due to the greater evening light. There’s also the founding claim that daylight savings time decreases the demand for electricity, although this has been thrown into major doubt by later research from Indiana, which actually found an increase in demand for residential electricity. As for the economy and crime, there is little research to suggest either of these effects. Advocates will cite the common sense nature of these ideas, but there’s not much actual empirical backing.
Daylight savings time may be ending soon, but it’s not clear if we’ll be that much better off. Public opinion and research agree that switching twice a year is harmful, but permanent daylight savings time has its own set of issues and a questionable set of benefits.