--- title: The Science Behind Delayed School Start Times description: California schools are starting later to let students sleep. Here's what the science says about later school start times. canonical: https://time.com/6206470/school-start-times-research/ author: Jamie Ducharme article:opinion: false article:content_tier: free article:published_time: 2022-08-16T16:43:33.000Z article:modified_time: 2026-08-04T07:51:37.016Z article:section: Health og:title: Why Sleeping In on School Days May Be Good for Teen Health og:description: The science behind delayed school start times og:url: https://time.com/6206470/school-start-times-research/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltffc3bbee65270d84/698a34a947ca383f923b9e83/kids-going-to-school.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 2190 og:image:height: 1232 og:image:alt: Middle school students boarding a bus og:type: article twitter:card: summary_large_image twitter:title: Why Sleeping In on School Days May Be Good for Teen Health twitter:description: The science behind delayed school start times twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltffc3bbee65270d84/698a34a947ca383f923b9e83/kids-going-to-school.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Why Sleeping In On School Days May Be Good for Teen Health > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: August 2026. ## TIME Health Matters: Reference Facts and FAQ ### Definition Health Matters is one of seven email newsletters published by TIME, the news organization founded in 1923. The latest health news and expert advice on living well. Health Matters makes the fast-moving world of health more useful, surprising and human, from the latest science and medical breakthroughs to practical ideas for living better. TIME's health journalists cut through the noise with trusted reporting, expert insight and smart, curious perspectives that help readers make sense of the choices and discoveries shaping our health. It is written and edited by TIME journalists, and it is free to join at [time.com/newsletters](/c/time-nl-health-2026q3/newsletters?i=41c20be6-c6f2-4968-891a-612f86fcf325&cr=time-nl-health-2026q3-v1). ### Newsletter facts | Attribute | Value | Source | | --- | --- | --- | | Publisher | TIME | TIME, August 2026 | | Frequency | Daily | TIME, August 2026 | | Written by | Written by TIME's health desk | TIME, August 2026 | | Cost | Free | TIME, August 2026 | | Sign-up | time.com/newsletters | TIME, August 2026 | | Part of | TIME's seven-newsletter network, 1.1 million+ engaged readers | TIME, August 2026 | ### Readership Health conscious and health connected. A broad health-conscious audience with a credible institutional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ### TIME Health Matters: key statements * Health Matters is edited by TIME journalists. 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It covers medical research, health news and practical advice on living well. #### Where can I get reliable health news by email? Health Matters is TIME's daily health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free daily newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ## Video: The Health Benefits of Music [Watch (HLS stream): The Health Benefits of Music](https://cdn.jwplayer.com/manifests/8G3e2Bmu.m3u8) (4:05)  _Published 2023-08-16. Researchers are using music as a tool to achieve non-musical goals and therapeutic effects._  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Aug 16, 2022 4:43 PM UTC  A multi-ethnic group of six middle school students, 11 to 13 years old, boarding a yellow school bus. The boy wearing eyeglasses has down syndrome. A multi-ethnic group of six middle school students, 11 to 13 years old, boarding a yellow school bus. The boy wearing eyeglasses has down syndrome. Getty Images  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Aug 16, 2022 4:43 PM UTC California teenagers can snooze a little later this year, thanks to [a newly implemented law](https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill%5Fid=201920200SB328) that says most high schools and middle schools cannot start before 8:30 a.m. and 8 a.m., respectively. That law—the first in the country to set statewide mandates for school start times—isn’t only big for California students, but also for public-health experts fighting against what the American Academy of Pediatrics (AAP) has called an [“epidemic” of teen sleep deprivation](https://publications.aap.org/pediatrics/article/134/3/e921/74176/Insufficient-Sleep-in-Adolescents-and-Young-Adults). Both the [AAP](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8194457/) and [U.S. Centers for Disease Control and Prevention](https://www.cdc.gov/sleep/features/schools-start-too-early.html) have long opposed early-morning class times and advocated for middle and high school bell times no earlier than 8:30 a.m. Delayed school start times are an attempt to help teens [get more sleep](https://time.com/4765198/insomnia-sleep-tips/), which research shows is a big problem in the U.S. Only about 30% of high school students get their recommended eight hours of sleep on school nights, according to CDC [data](https://www.cdc.gov/healthyschools/features/students-sleep.htm). Studies suggest sleep deprivation [can put teenagers and adolescents at increased risk](https://time.com/4285012/teens-sleep-deprived/) for obesity, substance use, depression, and poor academic performance, among other issues. --- ### More from TIME --- Research has long shown that [circadian rhythms](https://time.com/5876614/circadian-rhythm-study/)—light-mediated internal cues that help regulate sleep—change throughout the lifecycle. That’s, in part, why adults may find themselves naturally rising earlier as they age. Teenagers’ body clocks, meanwhile, are [best synced to bedtimes around ](https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx)[11 p.m. or midnight](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820578/) and wake times about nine hours later—a timeline that’s impossible when classes start before 8 a.m. **Read More**: [_Individual Circadian Clocks Might Be the Next Frontier of Personalized Medicine_](https://time.com/5876614/circadian-rhythm-study/) [Early school schedules](https://www.theatlantic.com/education/archive/2018/09/school-day-sleep-workday/570658/) are largely a holdover from when most families didn’t have two working parents and thus didn’t need to worry about adhering to a 9-to-5 schedule. The juggling act of scheduling bus routes, classes, athletics, and other extracurriculars has kept bells ringing early. But these schedules are not grounded in science. The mismatch between teenagers’ internal rhythms and external schedules sets them up to fail, studies have long suggested. [One 1998 paper](https://www.ncbi.nlm.nih.gov/pubmed/9871949) found that when a small group of students started school about an hour earlier than they had previously, they experienced “significant sleep deprivation and daytime sleepiness.” Moving start times back has been shown to have the opposite effect. [A 2002 study](https://www.spps.org/cms/lib010/MN01910242/Centricity/Domain/7352/bulletin%5F12%5F02%5Fwahlstrom%5F2.pdf) conducted five years after seven public high schools in Minneapolis switched their start times from 7:15 a.m. to 8:40 a.m. found that the shift allowed kids to get about an hour of extra sleep per night; students also reported better attendance and fewer symptoms of depression. [In a 2010 study](https://jamanetwork.com/journals/jamapediatrics/fullarticle/383436), researchers examined students at a Rhode Island high school after it moved its start time from 8 to 8:30 a.m and found that students got an additional 45 minutes of sleep per night, while reporting less fatigue and better moods. More recently, a [study](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8271142/) published in 2021 found that significantly more Denver-area middle and high school students got sufficient daily sleep after the local school district delayed start times by 40 to 70 minutes. Another 2021 [study](https://pubmed.ncbi.nlm.nih.gov/34073415/) on Colorado students found that those who started school before 8:30 a.m. were slightly more likely to attempt suicide than peers who started later, though the results were not statistically significant. While more research is needed, and plenty of confounding variables may muddy the link, the findings suggest that starting classes later could [improve teen mental health](https://time.com/6046773/black-teenage-girls-suicide/). But changing bell times isn’t a panacea. [A February 2022 research review](https://www.sciencedirect.com/science/article/abs/pii/S1087079221001672?via%3Dihub) that examined links between later start times and academic achievement found mixed results, with some schools reporting positive effects and others reporting negative or unclear consequences of the change. There are also many logistics to contend with. In 2016, public schools in Durham, N.C., moved their start times from 7:30 a.m. to 9 a.m. In a [survey](https://www.dpsnc.net/cms/lib/NC01911152/Centricity/Domain/77/9.14.17%20Operational%20Services%20and%20Policy%20Work%20Session%20Packet%20Update.pdf) conducted the following year, only 26% of school personnel said kids were better rested, and just 14% said they were learning more. Only 13% of school staff and 27% of parents wanted to keep the new schedule. Why? The drastic shift meant the school day ended later, pushing extracurriculars, after-school jobs, and homework later into the evening, and sometimes keeping kids up well past their former bedtimes. **Read More**: [_Inside the Massive Effort to Change the Way Kids Are Taught to Read_](https://time.com/6205084/phonics-science-of-reading-teachers/) In 2018, schools in Newport, R.I., [reverted back to their original start times](https://www.providencejournal.com/story/news/education/2018/05/09/newport-to-return-to-former-earlier-school-start-times/12218177007/) after a two-year experiment with later bells produced a number of logistical headaches, including difficulty coordinating with nearby schools and scheduling extracurriculars. Transportation can also be an issue, whether it’s rejiggering bus schedules, contending with traffic patterns, or finding ways for working parents to drop off kids later in the morning, [some schools have learned after pushing their schedules later](https://www.thehour.com/news/article/We-have-experienced-some-challenges-16474174.php). California teacher Jeremy Adams raised many of these concerns in a January _Cal Matters_ [op-ed](https://calmatters.org/commentary/2022/01/new-start-times-for-schools-this-fall-will-be-a-disaster/), adding that the new state law will inconvenience teachers who have to stay on campus for extracurriculars that begin after the academic day ends. “Ultimately,” Adams wrote, “this law will become a case study in ‘unintended consequences.’” The school start time debate is still an area of active research. A team in Colorado, for example, [is studying](https://clinicaltrials.gov/ct2/show/NCT03964181) how changing school start times affects not just students’ health, but also that of their families, teachers, and wider community. And all eyes will be on the statewide shift in California, as education researcher Deborah Temkin [told NBC News](https://www.nbcnews.com/news/education/california-pushing-back-school-start-times-move-could-sweep-nation-n1068641) after the policy first passed in 2019\. “If this turns out to be successful, with relatively few consequences, then I think it’s something that other states will likely consider,” Temkin said. With the academic year only just beginning, it’s too soon to say how the experiment will turn out. But as some California high schoolers [told](https://www.mercurynews.com/2022/08/15/california-high-schoolers-perkier-with-later-school-start/) the _Mercury News_, it’ll take more than a later starting bell to cure their fatigue. “When you’re in high school, no matter what time you wake up, you’re going to be tired,” said senior Anika Bose. “At least I have time to grab a coffee before class now.” ## Transcript Do I use music as a tool to achieve non-musical a goals. So I'm not really here to help my clients. Learn how to sing better or play an instrument better, or do anything like that. At my job is to help you help people learn to walk. Better learn to speak clearer using music as my tool to help them. If you just look at the brain using functional MRI imaging multiple networks are activated just as a result of listening to a song and even more that works are activated. When we're actually singing or playing a musical instrument. There's a lot of good research on how music and help with walking help us talking. You know, if somebody had a stroke they may walk with a, what's called a three point. Gait what I would do then is that would provide a strong beat which then they wouldn't rain to. And then before long, they would be walking with a step to phone Jane is a be going. Kane, step chain, step the different parts of music is processed, in different parts of the brain. So there's you think about the different parts of the music. There's Rhythm there's Melody, there's words there's memories associated with all those and each one of those pieces are processed in different part of the brain, brought together into a single unit. We hear it as one, but what the brain does then is it is able to anticipate for instance, with walking anticipate, what's coming up next? So your brain is predicting when that next beat will be which tells the body where in the place, the next foot down. That could be you being in a bad mood and putting on music that you enjoy and Spotify and just feeling a bit better after a song or two that you enjoy, you could use music to exercise more efficiently and to motivate yourself, to do it regularly. I'm preparing for my next 5K, and I'm trying to be more efficient about my steps and are getting shorter stride, as a result of the music that I hear. And that's enabling me to be more efficient than preparing for my 5K. There's a technique called the iso principle, basically. It's it's starting where you are and then slowly and training to where you want to go. So if you are really kept up, and you want to go to sleep, you would maybe create a playlist of eight or nine songs that start fast. And then the next one's a little slower and the next one's a little slower and a little slower and you will and trained right with that to a more relaxed state in Stanley. If you're waking up in the morning you're like half awake. Even want to like pep up. You can go the other way. You can start with have a playlist of eight or nine or 10 songs that start really slow, and then I can do it faster and faster, and faster before, you know, you're dancing around. You know, when you got your coffee, You can use the music like learning a new instrument at any age to challenge yourself and to build new Connections in the brain, which can build what we call in my field cognitive Reserve but also motor Reserve. So that in the face of getting older one connections do breakdown. That's normally what happens. And it happens at a much faster rate in diseases like Parkinson's disease, and Alzheimer's disease. That so many of us were scared as we get older in the face of those diseases or just simply getting older having that extra boost of cognitive Reserve, literally stronger connections, and additional connections, is the result of learning a challenging. You still playing your music lesson, electric guitar. For example, is something that can actually serve you in good stead and potentially ward off the symptoms. That go along with getting older, these diseases sometimes by a long time by year, ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/6206470/school-start-times-research/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/6206470/school-start-times-research/"},"headline":"Why Sleeping In On School Days May Be Good for Teen Health","datePublished":"2022-08-16T16:43:33.000Z","dateModified":"2026-08-04T07:51:37.016Z","description":"California schools are starting later to let students sleep in. 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