California becomes first state in nation to mandate later start times at most public schools

California became the first state in the nation to mandate later start times at most public schools.

Gov. Gavin Newsom signed the legislation into law Sunday.

The new law prohibits middle schools from starting before 8 a.m. and high schools from starting before 8:30 a.m.

It's based on studies that show teens are healthier and perform better when school starts later.

Districts will have three years to shift their start times.