Movement toward later start times in the United States shifted the school calendar for secondary students, delaying the first bell in many districts. The trend gathered momentum in the 1990s and has grown stronger in recent years, even before the pandemic highlighted mental health concerns among younger students. Dozens of districts nationwide are adjusting schedules, and currently California and Florida have enacted laws setting minimum start times for public schools: eight in the morning for students aged 10–13 and half past eight for those aged 14–18.
At least eight additional states are pursuing similar legislation, according to the National Conference of State Legislatures. For instance, New York prohibits starting any school before 8:30 a.m.
The idea of delaying class start times has broad support from academic associations and health professionals. Since 2014, the American Academy of Sleep Medicine and the American Academy of Pediatrics have considered sleep deprivation a public health issue, and the American Medical Association joined in 2016. The Centers for Disease Control and Prevention also cautions against too-early start times.
cardiac rhythms
The stance rests on science. Adolescents experience shifts in circadian rhythms that do not align well with typical school schedules. Data from 2020 show that 42% of schools begin before 8:00 a.m., and 82% start before 8:30 a.m., while 78% of high school students report getting less than eight hours of sleep on school nights. The recommended sleep duration for teens aged 13–18 is eight to ten hours. Sleep deprivation has been linked to poorer academic performance, obesity, metabolic issues, increased depressive symptoms including thoughts of self-harm, risky behaviors, sports injuries, and more traffic accidents.
studies
Analyses consistently show positive effects from later start times. For example, a 2016 Seattle study found that delaying start by one hour yielded an average of 34 additional minutes of sleep per night and a 4.5% improvement in grades, with higher participation rates. The researchers noted that asking a teenager to be awake by 7:30 a.m. is akin to asking an adult to function at 5:30 a.m. (Horacio de la Iglesia, et al., study author, cited).
Another study published in November last year in the Journal of Clinical Sleep Medicine analyzed 28 schools that delayed start times between 1999 and 2017, considering socioeconomic factors and race. It detected a 10% increase in graduation rates and a 7.44% increase for economically disadvantaged students, as well as a 3% rise in overall participation.
California led the way by approving legislation for the entire public system in 2019, and the model was followed in a law enacted this month. Florida implemented the same gradual approach to adoption over three years.
argument
Yet these changes sparked controversy. In both California and Florida, opposition comes from teacher unions, some school districts, and some parents who argue that decisions about programs should be made locally to reflect community needs. Critics also point to not being adequately heard and to a one-size-fits-all approach in some cases, an issue that even prompted former California Governor Jerry Brown to voice concerns about a rigid model, noting that rural areas may require exceptions.
Opponents often emphasize the economic impact on districts, including the need for more buses and drivers. They also highlight scheduling challenges for working parents, who worry about coordinating drop-offs, late classes, and potential conflicts with sports and extracurricular activities.