A bill that would require middle schools and high schools in California to start the school day no earlier than 8:30 a.m. is moving its way through the state Legislature.

Senate Bill 328, authored by Sen. Anthony J. Portantino, D-La Canada Flintridge, was approved Thursday by the Senate Education Committee. The bill is based on recommendations of the American Academy of Pediatrics and the Centers for Disease Control for the optimal time to start school for improved public health of teenage students.

“This makes a big statement to the education community that the state Senate Education Committee is using sound and definitive research to put the best interests of our students first,” Portantino said.

“Every school district around the country from every demographic and socioeconomic level that has moved teenage school start time later has seen a measurable, positive result for student achievement and student public health.”

The bill is opposed by the California Teachers Association, the state’s largest professional employee union, and California School Boards Association.

The average school day start time for California’s 3 million public middle and high school students is 8:07 a.m., according to Portantino, citing data from the Center for Disease and Control.

California school districts would benefit with later school day start times as funding is tied to attendance. The Los Angeles Unified School District estimated by improving the current attendance rate by 1 percent, the district would gain an additional $40 million per year, Portantino said.

“Every year we discuss as parents, educators, and legislators best practices and interests of the children and education,” Portantino said. “Well data is clear — starting the school day later improves the quality of education, health and welfare of our children.”