SACRAMENTO -- High school and middle school students in California may get a later start to the school day.State lawmakers on Friday approved a bill that would prohibit middle schools from starting before 8 a.m., while high schools couldn't start before 8:30 a.m.Supporters say the measure is needed to help deal with the epidemic of childhood sleep deprivation. The American Academy of Pediatrics says delaying school start times could improve sleep schedules.Opponents say it could negatively affect school programs held before and after school, and they believe school start times should be left up to school districts.Former Governor Jerry Brown vetoed a similar measure last year.If Gov. Gavin Newsom signs the current version, the new law would go into effect in 2022.