The Sacramento Bee reports that supporters of the proposal cited research concluding that later school start times improve student health. The American Academy of Pediatrics recommended in 2014 that middle and high schools start no earlier than 8:30 a.m. to offset sleep deprivation.
But Brown decided that school start times should not be determined at the state level.
"This is a one-size-fits-all approach that is opposed by teachers and school boards," Brown wrote in a veto message for Senate Bill 328. “Several schools have already moved to later start times. Others prefer beginning the school day earlier. These are the types of decisions best handled in the local community."
The California Teachers Association and the California School Boards Association lobbied against the bill, which narrowly passed the Legislature last month.
They argued that lawmakers should not dictate start times for diverse communities all over the state. The bill included an exemption only for rural communities.