Delayed High School Start Times Benefit Students

From prior research, educators and psychologists have long suspected that starting the school day a little later in the morning would greatly benefit students. In America, most secondary school days start between 7:30 and 8:30 am — meaning that children and teens have to get up pretty early each morning to make homeroom on time.

The problem is that children — and teenagers especially — forgo sleep in order to make these early start times. Because sleep is so vitally important to both our overall health and mental health, this results in less-than-optimal academic performance by teens early in the morning.

A new large-scale research provides more insight into the benefits of later start times for high school.

The researchers (McKeever & Clark, 2017) begin by noting that, “Sleep experts agree that school start times are not in synchronization with adolescent sleep cycles, affecting learning and overall well-being of students. Proven scientifically, the drive to fall asleep and alert from sleep shifts during adolescence. Previous studies suggest that adolescents need 9 hours or more a night to function at peak performance…”

Getting an inadequate amount of sleep every night results in some serious problems — especially for adolescents. For instance, the researchers note that a lack of sleep is associated with an increase in suicidal attempts, increase risk of substance abuse, depression, and suicidal thoughts. Even decreasing sleep by 1 hour per night has been found to increase a sense of hopelesness, suicidal thoughts, and substance abuse (Winsler et al., 2014).

It may seem that even such a small change of just one hour per night could result in such significant problems for teens, and yet the research has consistently shown these kinds of results. “Experts stress that the relationship between sleep disturbance and completed suicide is important to recognize and further suggest that this could be used as an indicator to initiate intervention and prevention efforts in teens at risk for suicide” (Goldstein et al., 2008).

Studying The Impact of a Later Start Time in the Real World

The current researchers decided to see how a later school start time would work in the real world. Not just with one or two classes in one school, but with 8 school districts and 29 high schools throughout 7 different states, resulting in a subject pool of more than 30,000 high school students. So this isn’t some small study whose results won’t be generalizeable; instead, this is a robust study with a simple pre-post test done in a within-subject design.

The researchers collected data on two primary variables — attendance and graduation rates — to see whether implementing a later start time to the school day would have any impact.

Most of the schools moved the start time of their school day forward approximately an hour, with a new start time between 8:35 am and 9:15 am.

Before the move to delay the start of the school day, average school attendance was at a 90 percent level, and the combined schools had a 79 percent graduation rate.

After the move to delay the start of the school day, average school attendance rose to 94 percent, and the graduation rate jumped to 88 percent.

While the study didn’t measure sleep specifically, it can be gathered from the evidence that a later start time to the school day would strongly suggest teens are getting more sleep. The researchers agree, saying, “Although this study does not specifically measure the amount of sleep, the results are consistent with prior research linking later school start times to more sleep.”

As the researchers conclude, “Every student should have an equal opportunity to graduate from school. If a delayed start time of later than 8:30 am promotes improved student access to attending, learning, and graduating, then all of society benefits because increased graduation completion impacts quality of life.”

“The connection between later school start times and more sleep is important, but the results of significant improvements in graduation rates allow practitioners to see the positive and socially important outcome of such a policy shift, increased graduation.”

We couldn’t agree more. If you’re a school (or school district) that starts your school day for high schoolers earlier than 8:30 am, this research provides additional data to support moving the start of your day to a later time. Not only will it likely benefit your students, it’ll probably also likely benefit your staff and teachers as well.



Goldstein TR, Bridge JA, Brent DA. (2008). Sleep disturbance preceding completed suicide in adolescents. J Consult Clin Psychol., 76, 84–91.

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

Winsler A, Deutsch A, Vorona RD, Payne PA, Szklo-CoxeM. (2014). Sleepless in Fairfax: the difference one more hour of sleep can make for teen hopelessness, suicidal ideation, and substance use. J Youth Adolesc., 44, 362–378.