Policy Factsheet

School-day Start Time

Reasons for Policy

  • Inadequate sleep may lead to poor school performance.1
  • Excessive sleepiness in adolescents can have a negative effect on cognition and mood.2
  • Excessive sleepiness in teenagers has been associated with an increased risk of automobile crashes.2

Community Groups

  • Local Government
  • Local School Board
  • Local School District

Policy Components

  • Later school-day start time

Desired Outcomes

  • Increased school attendance rates
  • Improved academic performance
  • Decreased school dropout rates

Level of Evidence Available to Evaluate Effectiveness of Policy

For all policies we describe on this website, we have applied the Standards of Evidence as defined by Flay et al. (2005) in the Standards of Evidence document published by Prevention Science.

The effectiveness level of this policy is 2: Policies with Consistent Evidence from High-Quality Observational Studies.

The levels of effectiveness as noted are:

  1. meets criteria for policy effectiveness (consistent, positive outcomes from at least two high-quality experimental or quasi-experimental trials using a comparison group or interrupted time series design);
  2. consistent evidence available linking policy with positive outcomes from high-quality observational studies only;
  3. insufficient evidence available for policy or policy components.

Achievable Results

On average, later school start times can achieve:

  • More total sleep on school nights for students attending schools with earlier start times.1
  • Improved attendance rates among high school students.1
  • Improved student attention and concentration.1,2
  • Decreased dropout rate among high school students.2

Results suggest that later school-day start times have beneficial effects on student attendance and academic performance. However, more rigorous studies are needed.

Community Examples

Minneapolis Public Schools, Minnesota, changed high school start time from 7:20 a.m. to 8:40 a.m.

Anderson County School System, Tennessee, approved delayed school start times

Links to Policy Examples

Minneapolis Public Schools Policies, §6132 School Day

Anderson County School System Rules and Policies, 1.101 Role of the Board

† Be sure to check with your state, county, and municipal governments regarding potential existing laws that may impede any new policy development. ‡Local governments and organizations may check existing state statutes and administrative codes for the authority to implement local policies.


1Wolfson AR, Carskadon MA (2003). Understanding adolescents’ sleep patterns and school performance: a critical appraisal. Sleep Med Rev., 7(6), 491-506.

2 Millman RP, et al. (2005). Excessive Sleepiness in Adolescents and Young Adults: Causes, Consequences, and Treatment Strategies. Pediatrics, 115, 1774-1786.

3 Flay, BR, Biglan, A, Boruch, RF, Ganzalez Castro, F, Gottfredson, D, Kellam, S, Moscicki, EK, Schinke, S, Valentine, JC, & Ji, P (2005). Standards of evidence: Criteria for efficacy, effectiveness and dissemination. Prevention Science, 6(3), 151-175.