California lawmakers narrowly passed a bill on Friday that would middle schools and high schools in the state to begin their classes at 8:30 am or later.

The bill, SB328, would give schools three years to apply, according to KPBS. Supporters say that studies have shown that later start times keep students healthier by allowing them to get more sleep and help them graduate.

“This is the single most cost-effective thing we can do to improve high school graduation rates,” Assemblyman Jay Obernolte, R-Hesperia, said.

Those opposed to the bill say that local districts should have control of school start times and not the state.

“When it comes to education, the farther away the decisions are made from the classroom, the worse those decisions are,” Assemblyman Jose Medina, D-Riverside, argued.

If signed into law by the governor, the rules would not apply to rural schools. Extra periods offered before the start of the school day would also be allowed.