An hour of the day will be unceremoniously snatched away on Sunday as we “spring forward” to daylight saving time.
Polling shows that more than half of Americans want to “ditch the switch” and prefer daylight saving over standard time by a margin of 10 to 20 points. But making that switch permanent would require an act of Congress, and while the Senate managed to pass a bill called the Sunshine Protection Act two years ago, the legislation never made it through the House. Worryingly, state legislators from Maine to the West Coast are now so fed up with waiting that they have introduced their own bills to remain on standard time permanently; states can do that without Congress.
But such a switch would be a mistake. It’s not just that our afternoons and evenings would be shrouded in more darkness, which often comes with higher crime, more vehicle collisions and fewer opportunities to enjoy the outdoors after work or school. There’s another problem with standard time, and it’s gone all but unnoticed until now. Last year, my research team showed that standard time leads to far more vehicles colliding with deer.
Vehicle strikes already kill millions of wild animals each year, and collisions with deer are the best documented because they are so common and damaging. When we looked at over one million collisions between deer and vehicles in 23 states across the United States between 1994 and 2021, we found these collisions are 14 times as likely in the two hours after sunset, compared to the two hours before. Deer behavior does not quite explain this, since they are equally active at dawn and dusk. But traffic volumes are higher in the evening, and it’s hard for us to see things in the dark. The hour-earlier sunset that comes with standard time is thus an expensive, traumatic way to control the deer population.
In all, we found that staying on daylight saving time year-round would prevent an estimated 36,550 collisions between deer and vehicles, whereas staying on standard time would add 73,660 of these collisions every year — a difference of more than 100,000. The human toll of staying on standard time would also be significant: Compared to year-round daylight saving time, year-round standard time would cause 100 more deaths, 6,000 more injuries and at least $3.5 billion in costs every year through increased deer-vehicle collisions alone.
Of course, more crashes with deer is far from the only cost of standard time. The number of fatal traffic accidents at night — caused by deer or anything else — is three times higher than it is during the day, and the dark increases the risk of pedestrian accidents by up to seven times. Permanent daylight saving time would prevent 366 fatal pedestrian and vehicle accidents a year with the help of brighter evenings during the 4.5 months of the year we currently spend on standard time. Conversely, staying on standard time for an extra 7.5 months each year would add about 610 fatalities — a difference of nearly 1,000 human lives.
Support for standard time has been growing in recent years, driven in large part by sleep scientists who argue it’s better aligned with humans’ circadian rhythm. One clever study compared sleep patterns of people living on either side of time zone boundaries as proxies for having sunrise come an hour earlier versus later. Those living in the proxy standard time regime got an average of 19 minutes more sleep per day, and the same study valued the associated health benefits at more than $2 billion. This is an impressive benefit, but not enough to outweigh the $3.5 billion this country would be paying to fix the damage incurred by deer collisions should we implement permanent standard time.
The trump card of standard time proponents is that we tried permanent daylight saving time once before — in 1974. After it went into effect, only 42 percent of Americans favored the change. Some parents disliked sending their children to school in the dark, and in only a few weeks, eight school children were hit by vehicles and killed in Florida alone, convincing lawmakers to reverse the shift.
Eight deaths may sound like a lot, but if you look at the country as a whole, morning fatalities of school children barely rose that January, from 19 to 20 — a shift that could be explained by normal year-to-year fluctuations. And if we were again to try making daylight saving time permanent, we’d save many more lives in the evenings.
I can understand why parents are worried about sending their children to school in the dark. But the best solution to that problem would be to have school start later. (Already many medical associations support this because of the variety of health benefits it could offer children, including the fact that they would get more sleep.)
If we move to permanent daylight saving time, we would potentially prevent hundreds of traffic deaths and tens of thousands of collisions between deer and vehicles. Robberies could drop by 7 percent.
Congress has the power to make this a reality. The Sunshine Protection Act was reintroduced to the House and Senate last March with broad bipartisan support — only to languish in the House Energy and Commerce Committee and the Senate Commerce, Science and Transportation Committee for a year. It’s up to the leaders of these committees to prioritize the issue this spring.
Every year, we gripe about the time switch, demand action and then return to our daily lives. But the toll on people and wildlife is too large to keep doing this year after year. And the longer Congress waits, the greater the risk of state bills for permanent standard time passing, making things worse instead of better. It’s time to spring forward permanently, and enjoy the benefits of brighter evenings year-round.