At 2 a.m. tomorrow, most of the nation will spring forward from standard time to daylight saving time. We’ll lose an hour of sleep. Residents of every state except Arizona (not including the Navajo Nation), Hawaii and five U.S. territories will have to pretend the sun rises and sets an hour later.
Our internal biological clocks will try to adapt to the new artificial time. Most of us will experience sluggishness, poorer concentration and increased moodiness for a week or longer. Many internal clocks that affect health and well-being will stay chronically out of sync from now until 2 a.m. on Nov. 3, when the nation will switch back to standard time. Four months later, we’ll have to go through the annoying ritual of switching to daylight saving time again.
That could change if legislators listen to scientists and vote to adopt permanent standard time — the schedule our brains and bodies prefer — not permanent daylight saving time as Sen. Marco Rubio (R-Fla.) proposed this week.
Adolescents, already the most sleep-deprived segment of our population, experience daylight saving time’s most detrimental effects.
One of our research, starting in the 1970s at Stanford University and continuing since the 1980s in the Sleep for Science Research Lab at Bradley Hospital and Brown University, shows that most adolescents need 8.5 to 10 hours of sleep every night to pay attention in class, absorb new information, drive safely, control their emotions and stay well.
Changes in the brain at puberty push adolescents to stay awake until 11 p.m. or later and sleep until 8 a.m. or later, if undisturbed. Many other studies have confirmed those findings.
In 2014, this research prompted the American Academy of Pediatrics to recommend that the nation’s middle and high schools start at 8:30 a.m. or later. Adolescents suffer from an “epidemic of delayed, insufficient, and erratic sleep,” the academy reported.
More recently, the Centers for Disease Control and Prevention found in a nationwide survey that 79 percent of U.S. high school students averaged less than eight hours of sleep on school nights.
Adolescent sleep needs seldom rank first among concerns school districts consider when setting high school start times. Local traffic patterns and after-school sports schedules usually garner more support. However, we send our children to school to learn. Ensuring that they are well-rested should be our top priority.
U.S. high schools start classes around 8 a.m. on average, according to a 2020 report from the National Center for Education Statistics, the most recent data available. Starting at 8 a.m. during daylight saving time is the same as starting at 7:00 a.m. standard time. Students nationwide must arise an hour earlier next week than they did last week to get to school on time.
Imposing daylight saving time on most of the nation means students around the country will wake up in the dark for much of the spring and fall. They will miss exposure to sunlight soon after awakening, which is critical for synchronizing internal clocks with Earth’s 24-hour light/dark cycle.
Internal clocks regulate numerous bodily functions, including alertness and sleepiness, appetite, body temperature, breathing, hormone secretion and reflexes. Students will struggle to follow daylight saving time, while their brains and bodies remain anchored to sun time, that is, standard time. Many will go to school in the dark.
Jared Saletin, associate director of the Sleep for Science Research Lab, is exploring the impact of sleep loss on learning in early adolescents. All of the lab’s research participants are volunteers who enroll in our studies with their parents’ permission.
In one study, first adolescents spend a week at home where they are scheduled to sleep for a healthy 10 hours each night. Next, they reduce their nightly sleep by two and a half hours. Each week, they take a series of tests similar to those they take in school to measure their learning.
While Saletin’s study is ongoing, preliminary results show that when adolescents get less sleep than they need, their reaction time slows and they experience changes in brain functioning.
Jeff Gentry, a professor of communication at Eastern New Mexico University who has studied the impact of body clock misalignment on driving crashes, believes the switch to daylight saving time poses added risks for inexperienced adolescent drivers, potentially diminishing their attention, decision-making, alertness and reflexes, especially when driving to school in the dark.
“Teen drivers are particularly vulnerable during daylight saving time,” Gentry told one of us in a phone interview. “Teens are more likely to be owls who take longer to feel alert in the morning than larks do.”
Sixteen- to 19-year-olds represent 3.6 percent of licensed drivers but account for 9.3 percent of drivers in all crashes and 6.3 percent of drivers in fatal crashes, the National Safety Council reports.
On Tuesday, Rubio reintroduced his previously sidelined Sunshine Protection Act, calling for daylight saving time year-round. This bill largely benefits commercial interests — restaurants, tourism, golfing and other leisure activities. Although Rubio asserts it’s good for business, it’s bad for human biology.
Adolescents — and the rest of us — likely would sleep better, perform better in school and sports and feel better more of the time if the nation adopted standard time year-round.
“Permanent standard time is the optimal choice for health and safety,” the American Academy of Sleep Medicine said in a recent position statement. Nearly 100 other health, safety, education, religious and community organizations in the U.S. and worldwide also recommend permanent standard time over permanent daylight saving time.
If you struggle to drag your child out of bed next week or hate getting up an hour earlier yourself, let your state and national legislators know. They have the power to lock our clocks on standard time.
Mary A Carskadon, Ph.D., directs chronobiology and sleep research at E.P. Bradley Hospital in Providence, Rhode Island. She is a professor of psychiatry and human behavior at Alpert Medical School of Brown University and the director of the NIH-funded Bradley-based COBRE Center for Sleep and Circadian Rhythms in Children and Adolescent Mental Health.
Lynne Lamberg is a science journalist and editor working with Mary Carskadon to expand public understanding of sleep, circadian science, and mental health. She is the book editor of the National Association of Science Writers.
