SAN DIEGO — Three San Diego schools have decided to push back start times by the end of 2019.

La Jolla High School, Muirlands Middle School and the San Diego School of Creative and Performing Arts will switch to later start times to improve sleep health for students.

Beginning with the next school year, La Jolla High and Muirlands Middle will start at 8:35 a.m. and let out at 3:15 p.m., principals of the two schools announced in a letter to parents this week.

Currently La Jolla starts at 7:35 a.m. and Muirlands begins at 7:30 a.m.

“Having a healthy start time has been shown to increase attendance, test scores and graduation rates,” La Jolla High Principal Chuck Podhorsky and Muirlands Middle Principal Geof Martin wrote in the letter. “In addition, healthy start times lead to decreased rates of emotional and behavioral problems, including anxiety and depression, along with corresponding increases in social, academic and athletic performance.” 

The principals cited research showing that later start times better align with sleeping patterns for adolescent students and thus help reduce sleep deprivation, according to The San Diego Union-Tribune.

RELATED: San Diego Unified moves towards later start times

In 2018, the San Diego Unified School board voted to have an 8:30 a.m. or later start time for its high schools by 2020. 

Critics argue that later start times complicate transportation and makes it difficult for parents to adjust their own work schedules.

Supporters point to science that shows later start times make kids healthier by letting them get more sleep and help them graduate.

According to the National Sleep Foundation, teenagers need about nine hours of sleep per night for optimal performance and development.