A proposal to make Daylight Saving Time (DST) permanent in the United States could significantly increase the number of children travelling to school before sunrise. Researchers at the University of Washington estimate that the change could result in at least two billion additional dark school commutes nationwide compared with the current system of switching between Daylight Saving Time and Standard Time twice a year.
The US House of Representatives passed a bill supporting permanent DST during the summer of 2026. Nineteen states, including Washington, have already approved the change in advance. However, the legislation remains stalled in the US Senate. If enacted, the change would eliminate the annual clock adjustment in autumn, extending evening daylight but leaving mornings darker between November and March.
To assess the potential impact on students, researchers examined 14 of the 19 states that had approved permanent DST. They combined school start times, student enrolment figures and geographical coordinates to estimate how often children would travel to school in darkness under the proposed system.
Washington alone could experience nearly 35 million additional dark school trips. Georgia showed the largest difference among the 14 states analysed, with an estimated 71 million more trips in darkness. Extrapolating the findings nationwide produced an estimate of at least two billion additional dark commutes.
Dark Mornings Could Increase Risks for Young Pedestrians
The researchers also analysed US traffic collision data and found that fatal crashes involving school-aged pedestrians were approximately twice as likely to occur during dark mornings as after sunrise.
Senior author Horacio de la Iglesia, a professor of biology at the University of Washington, questioned the benefits of a policy designed to preserve evening sunlight at the expense of morning daylight.
“It’s called the ‘Sunshine Protection Act’ because you get an extra hour of light at the end of the day. But you will take that hour from the morning. You could call it the Sunshine Destruction Act,” de la Iglesia said. “These dark mornings will inequitably affect children who have to go to school at a certain time. It’s a very tangible metric that anybody from any state or socioeconomic background can relate to. Nobody wants their kids to go to school in the dark.”
Morning light also plays an important role in regulating the body’s circadian clock, which influences sleep, mood and appetite. Reduced exposure to daylight after waking can interfere with these biological processes.
Lead author Guadalupe Rodríguez Ferrante, a postdoctoral scholar in biology at the university, explained why the team wanted to quantify the potential consequences.
“When we send kids to school in the dark, we are depriving them from an opportunity to get that morning daylight,” Rodríguez Ferrante said. “We were asking what’s the cost for these children. We wanted actual numbers, a real number of kids based on the geographic location of each school.”
Western Time Zones and Early School Starts Face Greater Impact
The analysis identified communities on the western edges of their time zones and districts with early school schedules as particularly vulnerable. These locations experience sunrise later relative to the clock, increasing the likelihood that students will travel before daylight.
Mississippi and Alabama illustrate the potential scale of the change. Schools in both states begin at an average time earlier than 8 a.m. Under the existing system, each state would record approximately two million dark school trips. Under permanent DST, that figure could rise to more than 20 million per state.
“Some districts probably never experience a dark commute under the current system, and, if this passes, suddenly they will wake up to this new reality that their kids are going to school in the dark,” Rodríguez Ferrante said. “Keep in mind that we used the actual start time listed for each school, and a lot of schools offer breakfast or other things before school, so the kids could be getting there even earlier.”
The nationwide estimate assumed that students would leave home at approximately 8 a.m. According to Rodríguez Ferrante, this is a relatively late departure time, meaning the calculation could underestimate the actual number of dark commutes.
“For the estimation, we assumed students would be leaving home around 8 a.m.,” Rodríguez Ferrante said. “That’s pretty late, so our calculation is likely an underestimation of the real number.”
Delaying School Start Times May Not Solve the Problem
The researchers also warned that permanent DST could undermine efforts to delay high school start times. These changes are intended to accommodate teenagers’ naturally shifted circadian rhythms, which differ from those of younger children and adults.
One proposed solution is to push school schedules later to ensure students travel after sunrise. However, de la Iglesia argued that this could have wider consequences for work schedules and evening activities.
“I’ve heard the argument, ‘If we’re in permanent DST, we can just delay the school start time to address these issues,'” de la Iglesia said. “Well, if we do that, you will end up going to work later. And everything is going to get delayed. You will get out of work an hour later, and you will miss the opportunity to enjoy your evening light. And essentially, we’re just going to be realigning everybody to solar time. That, by definition, is Standard Time.”
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