California first state to mandate school start times

California is the first state in the country to enact a statewide start time for public high schools and middle schools.

Gov. Gavin Newsom signed a bill that bans most high schools from starting before 8:30 in the morning and most middle schools from starting before 8 in the morning. The law will take effect starting in the 2022 school year. The law exempts "rural school districts," a definition to be worked out later.

The law is a victory for the "start school later" movement, which has been pushing schools to adjust their daily calendars for decades in the name of public health.

But teachers and school districts warn the law will burden them with extra expenses, like paying staff to chaperone students who still arrive early because of their parents' work schedules.