SACRAMENTO, Calif. — A bill signed into law Sunday will soon require California middle schools and high schools to adopt later start times. And while thousands of kids across the state are no doubt cheering in approval, not everyone is thrilled. “I say no, but I guess it’s already happening,” said one student who attends high school in San Diego. “It’s the change,” noted another mom of a Kearny Senior High student. “People don’t like the change.” Senate Bill 328 was introduced by State Senator Anthony Portantino (D-La Cañada Flintridge) earlier this year and reached Newsom’s desk last month. The new law, which will take effect in the 2022 school year for most California school districts, requires middle schools to begin classes no earlier than 8 a.m. and high schools no earlier than 8:30 a.m. “The reason for this policy change is to really align the way teenagers sleep,” said Dr. Rakesh Bhattacharje, Director of Pediatric Sleep Medicine at Rady’s Hospital. “They have what we call a delayed Circadian Rhythm where they do go to bed later and naturally wake up later. So, the idea of starting school earlier didn’t match.” Supporters of the bill have argued that starting classes later would not only enable students to get more sleep at ages when rest is essential for physical development but for mental development as well. Dr. Bhattacharje points out that the strategy is already being used in other states like Washington. “With that, they’ve noticed there’s less truancies,” he said. “Kids are making it to school in time; kids are sleeping more, which is important for mood, learning, physical health and kids’ grades have improved.” According to research by the American Academy of Pediatrics, waking up later in the day can improve academic performance among adolescents and boost students’ health. In a September 2014 issue of Pediatrics, the AAP called inadequate sleep in teenagers and pre-teens “an important public health issue that significantly affects the health and safety, as well as the academic success, of our nation’s middle and high school students,” adding that one way to address the issue was to delay school start times so students could log between eight and 10 hours of sleep each night. The legislation earned the support of more than 120 researchers and health experts across the United States, according to Start Schools Later, Inc.