Sleep is both the number one search on ParentData and a personal passion of mine. With babies and toddlers, a lot of the questions we have are about sleep training, about developing good bedtime habits, and so on — at least partly with the goal of helping us, the parents, get more sleep ourselves.
With older children, it’s more complicated. Many things get in the way of sleep — activities, phones — but it remains true that kids are often not sleeping enough, and this impacts their mental health, school performance, and other outcomes. The question is how to fix it. There are some changes that parents can make (fewer activities, phone limits), but today I want to talk about a policy change that might matter: delayed school start times.
The first part of this is a review of the evidence on the value of delaying school start times. The second part is practical: how could we actually get there?
What is the evidence on school start times?
First of all, what even constitutes a delayed start time? There is no specific definition, and many policy proposals are framed as “one hour later.” Later than what? you may ask. Unclear! However: generally it is taken to mean starting around 8:30 rather than, say, 7:30.
The evidence in favor of delayed school start times is strong. An example paper exploits variation across schools within a school district and shows that later start times are associated with more sleep and better grades.
My favorite individual paper example comes from a boarding school in Rhode Island that moved its class start time from 8 to 8:30 as an experiment. The researchers found positive changes — less sleepiness, fewer kids being late to class, less need for naps. Most notably, they found that the amount of sleep kids got went up by more than 30 minutes. It turns out that, having realized the value of sleep, kids started going to bed earlier. Keep this point in mind as you continue reading.
A summary paper looking at this evidence all together paints an overwhelmingly positive picture. Delaying school start times increases sleep, reduces drowsiness in school, reduces tardiness, and reduces student illness. There is evidence for improved academic performance, better reaction times, and improved mood and mental health. Car accidents seem to decline. There are reductions in weight and reductions in caffeine use.
There is a “wow” factor here, but I don’t think this should be surprising! Sleep is super-important for people, and as kids age into the teenage years, they have a harder time going to bed early but they still need sleep.
Perhaps unsurprisingly, the evidence shows that these later start times are more important for middle and high school students. One study followed a school district as it moved its start times to be earlier for elementary school students and later for middle and high school students. The result was a small decrease in sleep for elementary school students but no impact on daytime sleepiness or the share of students reporting sufficient sleep. Middle and high school students had substantially increased sleep duration (up to 45 minutes for high school students) and positive improvements in daytime sleepiness.
The bottom line is that it is quite clear that, unconstrained, we would start school later for older children than we typically do in the U.S. The question is: how could we get there?
How can we implement later start times?
Implementation of later start times is possible — many school districts have done it (that’s why we have evidence!) — but there are barriers.
One is the challenge of after-school sports and activities. A later start time with the same number of school hours means a later end time, which can crunch the time available for games and practices. A second challenge is parental work schedules. In a world where parents need to drop their children off at school, if work starts early, then it’s hard if school starts later. A third challenge is bus schedules; for districts with limited busing, moving high school start times later necessarily means moving some other (usually, elementary school) bus schedules earlier. It may not be impossible to do this, but it is work.
None of these challenges are impossible to get around. Schools could provide more help for families with drop-off (for example, offer early drop-off if necessary), and more high school students could get themselves out of the house alone. Bus schedules can be moved. Sports times can be adapted. But: doing this requires additional work by schools and families, and that can seem daunting. What we are doing now is “working,” so why disrupt it?
The core pushback should be that, in fact, it isn’t working. It’s just not working in ways that are hard to see. Making these ways visible is the key to change.
One way to see that is this study, which surveyed school administrators and found that a path to overcome resistance to changing start times was education about sleep and the benefits of the possible change. Also notable: the Rhode Island boarding school that changed its start time had intended it as an experiment that would be rolled back. But in the end, it was so successful that the school kept it — even though it did mean cutting some instructional time to make room for sports.
The bottom line
Changing start times isn’t a free lunch, or low-hanging fruit, or whatever your favorite analogy is. For school districts, it is work. And for parents, it’s probably also work — both advocacy work if you want your school to do this, and possibly schedule work if it does. But the benefits for our kids are substantial, and that makes it worth working for.
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I wish there was more data for elementary students. My district actually did shift middle and high school later due to California law. However, elementary school starts at the same time. I’m an elementary teacher and I would love to start an extra 20-30 minutes later. We do have paid morning care available starting at 7 am for parents who need to work earlier. I’d say maybe 30 out of 550 students are dropped off before school starts at 8:00. I would like to know if there are benefits besides sleep for elementary students such a decrease in the number of tardy students?
I think another factor that gets misses sometimes is that older siblings might be taking care of younger siblings. In addition, high school students are sometimes the employees in after school programs and without them those after school programs for elementary school kids would not exist. Another thing to consider when moving times.
I agree. I know there were concerns in our school district about who would take care of the younger siblings if they started school earlier and therefore got home earlier than their older siblings. The change has happened and has been generally well received, but that was certainly a consideration.