When Denver’s new Northfield High School opens next August, its students will report to their first class more than an hour later than students at most other district high schools.

The school’s planned 8:45 a.m. start time is a nod to the growing body of evidence that suggest teens are hard-wired to favor later bedtimes and do better academically when school schedules accommodate their natural sleep cycles.

Northfield Principal Avi Tropper said the decision to go with some version of a later start was based on abundant research, with community focus groups helping pinpoint the exact time.

“It’s pretty clear to me starting a school from the ground up…it’s just an opportunity from the beginning to do what works for students,” he said.

While later secondary start times are relatively uncommon, the concept is slowly gaining traction among educators in Colorado and across the country. In August, the topic got a burst of attention when the American Academy of Pediatrics, or AAP, published a policy statement advocating for middle and high school start times of 8:30 a.m. or later.

It was news that grabbed the attention of Denver school board member Michael Johnson, prompting him to send the statement to fellow board members and district staff.

“This is something we ought to look at,” he said. “This might be something that we could do that would be relatively painless…and we might be able to bump up student achievement just by changing the schedule.”

Johnson said he doesn’t envision a districtwide mandate for later high school starts, but perhaps a recommendation with implementation supports for interested schools.

Giving it a go

Among the small number of schools that have start times of 8:30 a.m. or after are Cortez Middle School and Montezuma-Cortez High School. An interim superintendent changed the previous 7:30 a.m. start to 8:50 a.m. in 2012 and at the same time changed the district’s four-day school week to a five-day week.

Jason Wayman, the high school principal, said adding Fridays back into the school week was the more controversial change, but the later start time drew some complaints too.

“I’ve gotten mixed feedback. You have a lot of kids who need the sleep and you have a bunch of kids who want out earlier because they have to go to work,” he said.

Other concerns, all fairly typical in the debate about later start times, include sports practices being pushed later, elementary schools starting earlier and tricky districtwide busing logistics. Wayman said because the district’s longer elementary bus routes are now completed before secondary bus routes, some of the high school buses arrive late.

Parent Sheri Noyes said her son, who graduated in 2013, liked the earlier start time better but her daughter, who is a junior, prefers the later start time. It gives the busy teen time before school to go to dance or track practice, and still make time for additional dance classes, or softball or soccer practice after school.

“I think all in all the late start time is good for the high school kids,” said Noyes. “I know it works for us.”

She said some families with elementary-aged children didn’t like the later start time at first because their older children were no longer dismissed in time to watch younger siblings after school.

“It wasn’t too friendly that way, but I think people have dealt with it,” she said.

Starting this year, the Harrison School District near Colorado Springs pushed back start times at all 20 of its schools, after a committee studied the issue for two years. High schools now start at 7:45 a.m. instead of 7:20 a.m, and elementary and middle schools now start at 8:35 a.m. instead of 8:10 a.m. (On Mondays only, middle schools start at 10:05 a.m. and high schools start at 9:15 a.m.)

Christine Lyle, the district’s public information officer, said the late start discussion originated with concerns from school board members and parents about high school start times, but the committee concluded last spring that later starts would be good for all students.

While the new middle school start times align with the AAP’s recommendation, the high school start times are well shy of the 8:30-or-after goal.

Lyle said “We didn’t quite hit that with our high schools…I think we will continue to look at the data and study it. Obviously, we made the change before that recommendation came out.”

Anecdotally, the later start times are making a difference, though she said it’s hard to untangle the impact of the new schedule from the simultaneous districtwide implementation of “Breakfast After the Bell.”

“Our teachers feel like attendance is better, tardies are down, students are more engaged during instructional time,” she said.

Reviewing the research

Early secondary start times have long been the norm at many schools. But research shows that students with such schedules get less sleep than they should, and both health and achievement suffer.

The August policy statement from the AAP noted that adolescents who get enough sleep—8.5-9.5 hours a night is recommended—are at reduced risk of being overweight or suffering depression, are less likely to be involved in car accidents, and have better grades and higher standardized test scores.

So why don’t teenagers just go to bed earlier? The short answer is that biology doesn’t let them. That’s because sleep-wake cycles shift when kids hit puberty, making it harder for them to fall asleep as early as they did in elementary school. Experts say it’s normal for teens to be awake till about 11 p.m.

“Everybody who has kids knows that teenagers don’t get up in the morning very easily,” said Johnson, who currently has two children in high school.

Only about 15 percent of the nation’s high schools have start times of 8:30 a.m. or after, and 40 percent start before 8 a.m. In Denver, most high schools start between 7:15 a.m. and 7:45 a.m, and none start after 8 a.m.

Change is hard

No matter how much scientific evidence there is to support later school start times, changing school schedules can be a hard process for families and schools. Aside from transportation, child care and extracurricular activity logistics, there’s plain old habit.

“My reaction is it’s probably inertia as much as anything,” said Johnson.

Even among the Northfield High community, which had no status quo to fall back on, there was some resistance to later start times. Tropper said some focus group participants said at first, “That’s impossible. It can’t work.”

After he presented findings from various studies, most people changed their minds. The school, which will have an extended day schedule will run from 8:45 a.m. to 4:45 p.m. with mandatory daily physical education. For student athletes, that PE time may count for some of their daily sports practice.

Northfield’s scheduling experiment could be closely watched in Denver.

“If they have a later start time maybe that’ll get other schools looking at it,” said Johnson.