The hidden consequences of permanent daylight saving time

• The Sunshine Protection Act, approved by the House on Tuesday, would keep clocks shifted one hour ahead, meaning later sunrises and sunsets year-round.
• Most Americans want to end the biannual clock change.
• Proponents argue the change will provide more light during the workday, lead to more time spent outside and provide a boost to the economy.

Reality check: Making this shift — if the bill passes the Senate — could have massive consequences for Americans.

• "A permanent move to DST would likely increase the population's risk for chronic diseases for years to come" because sunlight is key to health and sleep, Adrian Pristas, director of sleep medicine at Hackensack Meridian Health, told Axios in an email Wednesday.

Dark winter mornings

Permanently resetting clocks means the sun won't rise until 8 or 9 a.m. in the winter.

• Maps shared by meteorologists and weather experts show sunrise wouldn't happen until 8:25 a.m. in New York, and 9:01 a.m. in Montana.
• This means millions of children would go to school in the dark, and morning commuters would face darker drive times, experts say.

Between the lines: Darker hours could lead to increased depression, sadness and fatigue, research suggests.

• It could also make winter feel longer, experts say.

Damage to sleep habits

How it works: The delayed sunsets and darker mornings could impact sleeping patterns and general health, experts say.

• More people would be awake before sunrise, waking up in the dark and falling asleep later in the night, the AASM says.
• Morning light helps regulate melatonin and naturally wakes the body, according to the American Academy of Sleep Medicine.

What they're saying: "It is likely to upset most people's already delicate sleep schedules," Pristas said.

• "When you are sleep-deprived, your concentration is impaired and your mood is more volatile," he added.
• He also said sleep deprivation can create inflammatory issues that can lead to obesity, heart disease, diabetes and high blood pressure.

Children, school and the previous backlash

Flashback: Congress voted in 1973 to put the U.S. on daylight saving time for two years with then-President Nixon's support.

• But Americans largely hated the change.
• "The simple reason was that parents voiced concerns about their children standing more and more in the dark waiting for the school bus," reader Jon F. Gasper told Axios in 2022.

Congress later repealed the amendment due to the backlash.

Impact on Jewish and Muslim prayers

Case in point: The shift to permanent daylight saving time would lead to later sunrises, and that could have widespread impacts on Orthodox Jews who pray in the morning at a synagogue, The Forward reported in 2024.

• "If sunrise is late, religious Jews have to delay going to work or pray at work — neither of which is a desirable situation," Rabbi Zalmen Gurevitz, of the Rohr Chabad Jewish Center at West Virginia University, told The Forward.
• Some Muslim prayers and religious observances are also tied to sunrise and sunset and would be affected.

Traffic accidents and safety

By the numbers: Research shows that darker mornings are associated with an increase in traffic accidents and crash risk.

• Studies show a 6% increase in traffic fatalities immediately following the spring shift to daylight saving time.
• Other research shows that there's an 18% increase in adverse medical events caused by human error during that time, too.

Go deeper: Lo, the glories of standard time in June