The American Association of Sleep Technologists (AAST), given the compelling research currently available, strongly recommends that school start times for middle and high school students be delayed to 8:30 am or later to adequately accommodate student sleep requirements.

Statement of Support

The AAST, as an organization that educates and supports the sleep professionals who assist in the evaluation and follow-up care of patients with sleep disorders and provide individual and community education, strongly supports the Start School Later initiative that is underway across the country.  This initiative reinforces the importance of sleep; sufficient sleep quality and sleep quantity, and supports the quest for a healthier and more rested younger generation.  This is a most important initiative and as sleep professionals we believe it is critically important to address the sleep needs of our children.

Summary Statement

Research conducted by stalwarts of the sleep world has consistently reinforced the importance of sleep, sleep quality and sleep quantity. While it has been unfolding the secrets of sleep functions and benefits of adequate quality and quantity, it has shed ample light on the changes that come about naturally across the lifespan of human beings.

It is important to recognize that middle school students, teens and young adults require about 9 hours of consolidated sleep to function optimally (National Sleep Foundation [NSF], 2015). 

Expectations from community and school activities demand that they ignore their natural circadian requirements in order to fulfill their social and school obligation. These pressures could result in: attention deficits; cognitive impairment, affecting their problem-solving skills; driving to school drowsy; behavioral problems; depression; and irritability.

According to the National Sleep Foundation (NSF), data from the Federal Bureau of Investigation (FBI) points to high schoolers tending to be at high risk of being exposed to: violent activities; engaging in sexual activities; and recreational use of alcohol and drugs mostly between the hours of 2-4 pm when minimal adult supervision is available.

In light of all of the above mentioned reasons, pushing back middle and high school times combined with adequate education and support for parents, teachers and students alike would result in a healthier and more balanced younger generation more equipped to take on bigger challenges in life (National Sleep Foundation [NSF]. n.d.).


Adolescence (middle and high school students ages, 13-18 years) is a period when sleep patterns change significantly as a result of a delay of up to 2 hours in evening sleepiness (Carskadon, 2011).  This shift is a result of a change in the two main biological processes that govern sleep timing, known as Process S and Process C. “Process S” refers to the pressure or drive to sleep, and in adolescence there is a weakening in the buildup to sleep during the evening. Meanwhile, the biological clock known as “Process C” shifts later to also delay sleep onset. Both of these forces have the effect of delaying sleepiness until well after 11:00 pm in adolescents who need 9 to 10 hours of sleep to be rested (Carskadon, 2011). This creates a dilemma the following morning for students in need of a full night’s rest when the morning school start time is too early.

If adolescents are unable to fall asleep until very late at night or early morning, due to their changes in physiology and shift in sleep drive, they are unable to get the required sleep before school starts.  Since most middle and high schools start between 7:00 am and 8:00 am, they are unable to meet the sleep duration needed for their age groups in order to accommodate the delay in adolescent sleep phase.  Consequently, more than one-half of U.S. high school students and nearly one-third of middle school students average less than 7 hours of sleep on school nights (NSF, 2014).

Based on all of this, there is consensus among many national organizations in support of a change to establish a national school start time of 8:30 am or later, including the American Academy of Sleep Medicine, American Academy of Pediatrics, National Parent Teacher Association and the American Medical Association.

 When students begin school later, it has been shown that they sleep longer hours and can gain many benefits (Boergers, Gable, & Owens, 2014).  Nearly every school district that has tracked the impact of later start times has shown a comprehensive list of improvements, which include: improved mood (Dahl, 1999; Owens, 2010); improved attendance (Owens, 2010; Wahlstrom, 2014); increased graduation rates (McKeever & Clark, 2017); increased academic achievement (Wahlstrom, 2014; Edwards, 2012); and decreased rates of motor vehicle accidents (Wahlstrom, 2014; Vorona, 2015).

Given this compelling research, school start times for middle and high school students should be delayed to 8:30 am or later to adequately accommodate the sleep needs of adolescents who need 9 to 10 hours of nightly sleep and tend to fall asleep well after 11:00 pm as a result of the biological changes that occur during this developmental phase.

Some examples from successful communities include:

  1. Oakland County’s Berkley School District in Michigan moved their start time from 7:40 am to 8:20 am (Chambers, 2018).
  2. Edina, Minnesota on the outskirts of MN was the first district in the nation to embrace a later start time for HS students 19 years ago.  HS starts at 8:30 am.
  3. Jackson Wyoming HS moved their start time of 7:30 am to 8:55 am (Rosenberg, 2015).
  4. Seattle Washington delayed start time by 55 minutes (from 7:50 am to 8:45 am) in 2017 (American Association for the Advancement of Science [AAAS], 2018).
  • Adding a 0 period, (i.e., an optional study hall) at the beginning of the school day to increase scheduling flexibility.
  • Holding some extra-curricular activities before school, concurrently with an optional enrichment period/study hall at the start of the school day (this is popular in TX where many High Schools start at 9 am).
  • Replacing after-school remediation with during school (i.e.: lunch) or before school help (reported that teachers preferred this to having to stay after school), so athletes could proceed directly to practice instead of having a gap between dismissal and practice.
  • Flip elementary and secondary start times, start all schools later, and share buses with neighboring districts. This solution requires no extra buses or drivers, just a change in the order of pickups.
  • Implement a shift to public transportation for older students. Many districts have found they can actually save money by buying student bus passes and eliminating a large portion of their yellow bus fleet.


National Sleep Foundation (2015). National Sleep Foundation Recommends New Sleep Times.  Retrieved from

National Sleep Foundation (n.d.). Backgrounder: later school start times. Retrieved from

Carskadon, M.A. (2011). Sleep in adolescents: The perfect storm. Pediatrics Clinics of North America, 58, 637-647.

National Sleep Foundation. (2014). Sleep in America Poll. Sleep in the modern family. Retrieved from

Boergers, J., Gable, C.J., & Owens, J.A. (2014). Later school start time is associated with improved sleep and daytime functioning in adolescents. Journal of Developmental & Behavioral Pediatrics, 35(1), 11-17. doi:10.1097/dbp.0000000000000018

Dahl R.E. (1999). The consequences of insufficient sleep for adolescents. Links between sleep and emotional regulation. Phi Delta Kappan. 80, 354-359.

Owens J.A., Belon K. & Moss P. (2010). Impact of delaying school start times on adolescent sleep, mood, and behavior. Archives of Pediatric & Adolescent Medicine. 164, 608-614.

Wahlstrom K.L., et al. (2014). Examining the impact of later high school start times on the health and academic performance of high school students: A multi-site study. Center for Applied Research and Educational Improvement. Final Report. 1-71.

McKeever, P.M. & Clark, L. (2017, April). Delayed high school start times later than 8:30am and impact on graduation rates and attendance rates. Sleep Health. 3(2):119-125.

Edwards F. (2012). Early to rise? The effect of daily start times on academic performance. Economics of Education Review. 970-983.

Vorona R.D., et al. (2015). Adolescent crash rates and school start times in two central Virginia counties, 2009-2011: a follow-up study to a southeastern Virginia study, 2007-2008. Journal of Clinical Sleep Medicine. 10, 1169-1177.

National Sleep Foundation. (n.d.). Eight major obstacles delaying school start times. Retrieved from

Chambers, J. (2018, August 15). Some Mich. schools delay start times to help teens sleep, learn. Retrieved February 21, 2019, from

Bowden, J. (2018, September 01). California lawmakers vote to delay school start times to allow students to get more sleep. Retrieved February 21, 2019, from

Rosenberg, M. (2015). Feature: Clearing The Snooze Hurdles
What three districts did to create later school start times to address teenagers' sleep patterns. Retrieved February 21, 2019 from

American Association for the Advancement of Science. (2018, December 12). Delayed high school start times in Seattle increase sleep, grades and attendance. Retrieved February 21, 2019, from

National Sleep Foundation (n.d.). How Much Sleep Do We Really Need? Retrieved February 21, 2019, from