In July 2026, the US House passed legislation to make daylight saving time (DST) permanent. But a new analysis of the consequences of the "Sunshine Protection Act," reported in the Cell Press journal Current Biology on October 29, finds that this legislation would come with serious safety consequences for millions of schoolchildren across the US who would have to leave for school before sunrise, when fatal crashes with pedestrians are more likely, for much of the school year. Permanent DST would lead to more than 2 billion pre-sunrise commutes for children, and students who walk or take the bus to school would face an increased risk of early morning crashes.
"Permanent DST would move the school day earlier relative to the sun without changing a single bell schedule, putting millions of children on streets and at bus stops in the dark for weeks or months every year," says Horacio de la Iglesia of the University of Washington, Seattle.
Much of the public debate around permanent DST has focused on the light available during the evening. But the researchers say that mornings are a critical time for schoolchildren, who would generally return home during light hours under any clock policy. The de la Iglesia lab has long studied the way school start times affect adolescent sleep, including the move in Seattle and many other school districts to later secondary school start times. When the US House passed the Sunshine Protection Act in July 2026, the team realized that no one had investigated how many children would be sent to school in the dark under the new policy.
"The US has tried this before," says Guadalupe Rodríguez Ferrante, also at the University of Washington, Seattle. Year-round DST took effect in January 1974 and was abandoned that October, in part because of public concern over dark winter mornings and children traveling to school. "All of today's students, and most of today's parents, have never lived through a winter on DST, so experience with the current seasonal system does not tell us what permanent DST would be like."
The researchers gathered school start times in 14 states with permanent DST along with local sunrise times. They counted the number of pre-sunrise commutes in each location and found that there would be about 356 million more pre-sunrise school commutes with the move to permanent DST. When they broadened their approach beyond these states to the entire US, they found that the Sunshine Protection Act would lead to more than 2 billion dark morning commutes for children. They also found that students in both northern and southern states would be impacted, and Georgia had the highest number of pre-sunrise school commutes of all states analyzed.
The team then analyzed fatal-crash records in the US over a decade and found greater odds of crashes involving pedestrians on dark mornings. Among fatal morning crashes, those involving pedestrians aged 5 to 18 were more likely when it was dark. The data suggest that permanent DST would lead to more children at an increased risk of early morning crashes, say the researchers.
"The burden of permanent DST is likely greatest for children who walk, wait for buses, or arrive early for school breakfast programs, which disproportionately serve lower-income families," says Ferrante.
The US's current system of shifting the clocks forward and back also doubles the number of dark school mornings compared with permanent standard time (ST). Permanent ST is not only safer for children going to school, the researchers say, it also keeps students' solar, biological, and social clocks best aligned, according to the team's past research.
"The name 'Sunshine Protection Act' is misleading," says de la Iglesia. "No clock policy adds a single minute of daylight. It only changes when that daylight is available, and permanent DST moves an hour of light out of the morning, when children travel to school, and into the evening."
