With a population of just over 11,000, Dobbs Ferry in New York is your typical sleepy town, except for one thing - when the first school bell rings, kids actually feel awake.

Prior to the 2015-2016 school year, Dobbs Ferry middle schoolers started at 8:15am and high schoolers at 7:30am. Under the new policy, both schools now start approximately 30 minutes later and end 15 minutes later.

In making those changes, the Dobbs Ferry School District joined a small but growing group of middle and high schools around the US that have started pushing back their start times in an effort to combat grogginess.

The changes are bolstered by a mountain of sleep science research that says pre-teens and teenagers are some of society's most sleep-deprived people and would actually do better in school with more rest.

These forward-thinking schools are finally listening - and letting kids sleep in.

What happens when you start later?

new study involving 30,000 high-school students across 29 schools in seven states found that graduation rates and attendance rates both went up in the two years after schools pushed start times to at least 8:30am.

Dobbs Ferry superintendent Lisa Brady tells Business Insider that the schools there have experienced tremendous benefits.

Following a survey issued at the end of the 2015-2016 school year (the first full year with later start times), Brady says, "It was clear from both the parents and the kids, overwhelmingly, that the mornings were just less stressful."

Many of the kids reported having more time to eat breakfast and get ready for school, while parents said they didn't have to drag kids out of bed or yell at them to hurry up.

Once students got to school, they felt more alert. At night, they tended to reported going to bed at the same time, even though the new schedule freed up an extra 45 minutes.

Other schools have seen similar benefits. In Seattle, 85 percent of middle and high schools in the 2016-2017 school year swapped start times with the elementary schools.

Now the older kids start at 8:45 while the youngsters start at 7:55.

Kira Hoffman, an eighth-grader at Jane Addams Middle School, told KUOW that she "no longer feels super-rushed or worried about how much I've slept, or when I'm going to get to school, or if I'm going to be late".

In Pennsylvania, a new hope

So far, hundreds of schools in 44 states have jumped on the late-start bandwagon, according to advocacy group Start School Later, which has been compiling a list of US schools and districts that have pushed back the first bell.

One of those is Solebury School in New Hope, Pennsylvania, where Director of Studies Rick Tony pushed for a robust set of changes to the school schedule.

Kids at Solebury, a private boarding and day school, now start at 8:30am most days, and 9:00am on Wednesdays.

In years past, the first bell sounded promptly at 8am.

The school also moved from six 50-minute classes per day to four 80-minute classes. With fewer teachers to assign homework, Tony says, kids can still enjoy their nights even if they get home slightly later.

"Every time we ask for feedback, the results come back 10 to 1, positive to negative," he tells Business Insider.

Tony also teaches maths, and says his students are already producing better work on a more consistent basis, even though the schedule is just six months old.

Around campus, he says, kids seem more relaxed since they're not juggling as much work early in the day.

"The freneticism is definitely reduced this year," he says, adding that he plans to follow up with teachers to get harder data about student achievement.

The downsides of delaying start times

Negative responses to later start times are rare, but they do happen. Lisa Brady says some parents in Dobbs Ferry have found it harder to complete the necessary morning rituals and still get to work on time.

Meanwhile, Rick Tony says the issue at Solebury is finding enough buses for kids.

In both cases, officials say parents have the option to drop their kids off at school before the first bell so they can eat breakfast, charge their devices, or just hang out.

Brady has also found challenges with after-school athletics and clubs.

In years prior, teams had no trouble getting to away games. Now they have less time to get there, and they have to deal with worse traffic.

"The kids feel really rushed," she says.

Many kids also say they have less time to do homework once they finally get home. Brady says the Dobbs Ferry schools are brainstorming potential changes to the school day similar to those made at Solebury.

It takes a village

In districts where schools have not started to take sleep science research into account, parents have begun to speak up.

An op-ed published in the Los Angeles Times in September 2016 included voices from frustrated parents who were fed up with coaxing bleary-eyed adolescents to get dressed.

"I have been saying for years that kids, especially high school students, should not be expected to be in their seats trying to learn anything in the early morning hours," a parent named Paula Del said.

When asked why more schools have yet to take her district's lead, Brady speculated that it has something to do with generational pride.

Even if the science is rock-solid, many administrators and parents simply don't pity the sleepy teen. Waking up is hard, but it's a part of life.

"I get that years ago we all walked 100 miles in the snow to school," Brady says.

"But we know better now about the adolescent brain, and we know about their natural sleep rhythms being different than adults'."

This article was originally published by Business Insider.