Twice a year we all get together and do something rather odd. We look at the clock, decide we don’t like what we see, and just . . . change it. We then proceed to go about our lives doing everything either an hour earlier or an hour later until we change our minds again. This works for us because we are all in on it, but why do we do it? We in the U.S. are not the only ones to practice this particular brand of black magic—70 countries currently observe Daylight Saving Time (DST) to varying extents—but subtle differences in practice mean that in addition to different time zones, the potential combinations of time differences between the countries of the world are myriad. It wasn’t always like this—there must be a reason for this ritual.
Let’s briefly consider the origins of this mass hysteria. Humans have been keeping time more or less forever, but reliable mechanical timekeepers (a.k.a. clocks) have only been around for a few hundred years. Timekeeping used to be almost completely localized and a standardized time was never really needed until the advent of the railways, where even small disagreements could lead to disaster. By the time the 20th century rolled around, people in the developed world lived and died on the clock. In 1895 George Hudson was the first to suggest that standardized time might serve us better if it were adjusted seasonally to leave us more daylight to enjoy in our after work hours. In 1916, The German Empire and the Austro-Hungarian Empires became the first to implement DST, but for decidedly more practical purposes. Adjusting schedules to better utilize the daylight hours was a crucial measure to save coal and other resources during WWI. The other combatants soon followed suit. Most countries abandoned it after the war, but with the outbreak of WWII got right back on the bandwagon. It was touch and go after that war too, but eventually most countries either settled on a standardized observance or abandoned DST all together.
The reasoning is sound—it really is a swell idea if we assume DST does what it’s supposed to do (don’t worry, we’ll get to that). Saving energy is good, whether from an environmental or an economic standpoint. And who doesn’t want more daylight after work? There are few things worse that going into work and heading home never once seeing the sun. Besides, sunlight is good for us. Moderate exposure helps our bodies synthesize vitamin D and can alleviate the effects of depression, specifically due to seasonal affected disorder. Proponents also point out that more daylight can lead to less crime. And even if only half of these benefits materialize, why not make the change when it costs nothing?
It all sounds great but we should examine the assumptions needed for this story to hold up. The traditional justification is that the benefits of coordination and standardization outweigh any inconvenience, even in the absence of solid evidence of DST’s efficacy. The problem is that the world we live in is not the same world DST was designed for. The world ran on coal in the late 19th century. Cars were a novelty. The Ottoman Empire was a thing. Europe and America were industrial economies, rather than the service-based economies they have become today. We actually have the tools to measure the effects of DST. The primary selling point—the energy saving effect—appears to be more or less nil in the modern world. Some studies have shown modest savings on the order of a percent, but just as many have shown either no change, or an increase in energy consumption. Most of the energy saved comes from lighting while most of the waste comes from increased driving and air conditioning.
Speaking of driving, proponents “fall back” on the claim that DST can help reduce accidents by shifting our commutes to a time with more ambient light. Indeed the U.S. Department of Transportation identified almost a full percentage point reduction in traffic fatalities while a later study by the Insurance Institute for Highway Safety found a similar decrease in deaths. More recent research, however, has shown the opposite. In fact, there appears to be a clear spike in fatalities on the Monday following the “Spring forward,” thought to be due mainly to sleep disruption. But wait it gets worse. Multiple studies have shown that heart attacks spike in the days following the spring transition – by as much as 25%. Russia cited an increase in suicides when they decided to stay on summer time, a move that Florida is currently considering as well. The aforementioned lost sleep—the average American loses 40 minutes of sleep when we spring forward—is the likely culprit behind these and all sorts of problems because, well, sleep is important. A huge chunk of the population is chronically sleep deprived and it’s known to negatively impact almost every aspect of your health. The added disruption is just needless harm.
That’s a lot of solid evidence that DST causes more harm than good, and a conspicuous lack of evidence that it provides anything close to the promised benefits. Beyond that, it’s absurd. Instead of just adjusting our schedules, we take it upon ourselves to alter time itself? While it’s true that time and space are but an illusion—the imperfect framework our puny brains impose on reality to make what sense of it they can—we should still treat such immutable constants as we have with the respect they deserve. At the end of the day, the government came into my house last night and stole an hour from me. And that’s not OK.