When clocks across most of the United States “sprang” forward on 9 March to mark the start of daylight saving time, many people woke up feeling groggy, irritable, and like they had just lost an hour of precious sleep. Those grievances—along with a growing body of research linking clock changes to negative health impacts—are part of why 54% of people in the United States are eager to abolish the century-old practice.
If the U.S. sunsets daylight saving time, however, what will take its place? Some legislators have proposed making daylight saving time the national year-round standard, which sleep researchers oppose on the basis that its extra-dark mornings and extra-bright evenings would dangerously disrupt people’s sleep. Many medical and scientific organizations instead advocate for permanent standard time (an option that, according to recent polls, is also preferred by nearly half of U.S. residents).
But there isn’t consensus within academic circles: In a provocative paper published last week in Royal Society Open Science, two physicists argue that the current system’s problems may be overblown—and that we should think twice before getting rid of seasonal clock changes.
Why do we have this clock system in the first place? What are the risks and health impacts of daylight saving? And what are the alternatives? Here’s what we know.
