Changing the clocks: the trick of living on summer hours forever

The U.S. senate approved an initiative that would put an end to changing the clocks back in winter. The decision now awaits the approval of Congress and the president. But experts argue for keeping the winter schedule

Cambio de hora
Employees with the Architect of the Capitol wind the Ohio Clock in the U.S. Capitol in Washington.Joshua Roberts (REUTERS)

Ed Markey, the 75-year-old Democratic senator, doesn’t exactly carry himself like a TikTok star. But on March 15, he decided to record a short video for the platform to celebrate that the U.S. The Senate had unanimously approved starting the process to end the time change. In the video, strutting like a father at his daughter’s wedding and with the Capitol in the background, he exclaims, “We’re walking on sunshine!” The senator, who cosponsored the bill with Florida Republican Marco Rubio, tweeted out an accompanying Spotify playlist that includes Janis Joplin’s version of Summertime, the Rolling Stones’ Time’s On My Side and Stevie Wonder’s You’re The Sunshine of My Life.

Markey’s enthusiasm seems justified. The law will clearly affect Americans’ daily lives: if it is approved in Congress, where its future is uncertain, and president Joe Biden ratifies it, the United States will remain forever in Daylight Savings Time. Goodbye to changing the clocks in November and March.

The unanimous vote–which in itself deserves a celebratory dance in a polarized America–comes a few days after the country switched forward its clocks to lose an hour of sleep. This week brought the end of the winter schedule. Everyone is happy–except the scientific community.

“It’s a decision made with the best intentions, but in the wrong direction,” Erik Herzog, professor of Biology and Neuroscience at the Washington University of St. Louis, explains in a phone conversation. Like other experts who have spoken up in the ongoing debate in the U.SHe agrees that changing the clocks twice a year isn’t a good idea. But he says that if we have to stick with one option, it’s better to stay with the winter schedule. “There are plenty of public health, security and economic reasons,” he says. “[This change] will force us to wake up at night for a significant part of the year, with the sound of the alarm clock instead of the sunrise.”

Herzog leads a nonprofit organization called Save Standard Time. They want to preserve the winter schedule, because they believe it’s best for “health, safety, education, productivity, wages, environment, and civil liberty.” The organization was created in 2019 by Jay Pea, a retired software engineer from San Francisco who describes himself on Twitter as an “amateur astronomer [and] circadian health fan.” The organization intends to influence a debate that has intensified in recent years. In 2018, the European Union approved the end of the time change after a poll of 4.6 million people, of whom 84% voted in favor. But the initiative hasn’t yet been implemented in the 27 member countries, and this Sunday, Spain will once again jump from two A.M. to three.

Herzog calculates that, of the seven million humans on the planet, “six [million] live on the correct schedule.” The rest–like most citizens of Europe and the United States, except those in Arizona, Hawaii, Puerto Rico and other territories–change their step twice a year. Mexico has also participated since 1996, this year changing their clocks on April 3, though current president Andres Manuel López Obrador doesn’t like the idea–or the motive of conserving energy. Chile also shifts their schedule that day, except for the Magallanes region and Antarctic. And those who once changed their clocks and stopped doing so have chosen the winter schedule. Argentina, which ended the practice in 2009, considering the energy savings insignificant and because in regions near the Andes the sun set close to midnight in the summertime. In Brazil, Jair Bolsonaro eliminated the time change two years ago, arguing that it didn’t save enough energy to justify the disruption of biorhythms. Countries closer to the equator, like Colombia, don’t deal with the problem: there the sun rises and sets with little variation all year round.

The United States senators’ initiative was already tested out during Richard Nixon’s presidency in 1974, at the peak of the oil crisis. “T was a disaster. It was approved as an extraordinary savings measure [more light, less energy consumption] for a two-year period, but it was eliminated before the time was up,” David Prerau, a MIT-educated software engineer and author of Seize the Daylight, explains in a phone conversation.

Prerau has advised several U.S. administrations on the issue. He says that the practice of changing the clock twice a year was, like so many other things, originally an idea of Benjamin Franklin’s. It started in England at the beginning of the 20th century. During the two World Wars, it became more widely adopted to increase production. In some places, it stuck. “It varied from state to state, even from city to city,” he explains. In his book Prerau recounts that, in the early 70s, a 50-kilometer bus ride between Steuebenville, Ohio, and Moundsville, West Virginia, took passengers through seven different time changes. Today, the continental United States is divided into three zones. In 1966, local practices were aligned, and in 2007, the current system was standardized: eight months in the summer schedule and four in the winter one. For Prerau, who doesn’t support the senators’ idea, this is the ideal system. “It’s not perfect, but I think staying as we are is  the best option. We don’t lose extra hours of light in summer, and we don’t have to wake up at night in the winter,” he says.

That 1970s experiment came too soon for the scientific discipline of neurologist Anne Marie Morse of the American Academy of Sleep Medicine. “We can’t know how it affected people’s health, because we lack the data,” she clarifies in a phone conversation. But we do know, she adds, the effects of a change like this weekend’s in Spain: “Traffic accidents, heart attacks and other ailments increase, as well as hospital admissions.” “That is proven to happen in the days following the start of daylight saving time,” continues the expert. “While we don’t know what effects it would have if it were made permanent, we are certain that it goes against our circadian rhythms, and we suspect that it would have psychiatric consequences, such as depression, mood swings or anxiety, not to mention that certain places will feel it even worse.” Prerau calculates that in cities located in the westernmost part of the time zones, such as Indianapolis, Salt Lake City, Seattle or Detroit, the sun will rise as late as 9:00.

So why did the senators vote unanimously, amidst so much overwhelming medical evidence? On the one hand, there is the populist reason. “People associate DST with spring and summer. Who doesn’t love those seasons?” Morse asks. And then there are the financial reasons. Herzog advises following the money. “The golf, tourism and candy industries support later nights throughout the year,” explains Herzog, recalling that Marco Rubio, perhaps the senator who has most passionately defended the new law, comes from Florida, where those industries are powerful. Curiously enough, it was in Florida, the Sunshine State, that an increase in children getting run over on their way to school in the dark provoked a furious reaction the last time the United States tried to switch to an endless summer.


More information

Recomendaciones EL PAÍS
Recomendaciones EL PAÍS