First bell in a new Gwinnett high school sounds at 7 a.m., which requires some teens board the bus before 6 in the morning.

Is that too early? Science and probably a few parents would say it is.

One parent told me she was surprised Gwinnett County’s newest high school, Paul Duke Stem in Norcross, ignored the science showing teens fare better with later school starting times.  First period at the new school commences at 7.

The August opening of Paul Duke relieved overcrowding at Norcross High. The two schools share school buses, according to the parent. "Given the number of students riding these buses, and the first period first bell of 7:00 a.m. at Paul Duke, the high school bus is picking teens up in my neighborhood between 5:50 and 5:55 a.m," said the mom.

In writing about Paul Duke, which emphasizes science, technology, mathematics and engineering, the AJC described it as a school "with an eye to the future."

“However, this school, focusing on STEM and supposedly focused on the future, is operating in the past in relation to the current science on teen sleep schedules and the impact of early school start times,” said the parent.

I agree. The American Academy of Sleep Medicine, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention concur that high schools should start no earlier than 8:30 a.m, maintaining earlier start times lead to more missed school/missed classes, put sleep deprived new drivers on the road and adversely affect the physical and mental health of adolescents.

In its position paper endorsing later starting times, the American Academy of Sleep Medicine cites research evidence of reduced daytime sleepiness, increased engagement in classroom activities, reduced first-hour tardiness and absences and reductions in crash rates.

I have written about this issue many times, prompting a standard response from readers that we’re coddling kids since getting up at dawn is part of living in the real world.

But the real world is changing with many companies creating flexible schedules. Besides, the science indicates that graduation and attendance rates improve when schools start later, and that ought to be a key consideration.

After seven high schools in Minneapolis began classes at 8:40 a.m. instead of 7:15 a.m., a study found the students got more sleep and missed fewer classes. In a more recent study, researchers found that two years after later starting times were launched in high schools across seven states, average attendance rates and graduation rates increased several percentage points.

A few years ago, an Emory sleep expert told me teens are programmed to stay up late. Adolescents generally need 8.5 to 9.5 hours of sleep per night. During puberty, however, developmental changes in the circadian timing system and the homeostatic sleep system push back the time adolescents can fall asleep. This shift to later bedtimes --combined with early first bells -- produces sleep-deprived students.

While we could attempt to change the natural sleep patterns of teens and force them to bed earlier, the Emory researcher said it would be hard. The smarter alternative: Delaying the start of school.

That's what lawmakers in California tried to do this fall, passing a bill that would have mandated later school start times in most middle and high schools. Gov. Jerry Brown vetoed the bill, which would have banned starts before 8:30 a.m., saying it was too sweeping.

Seattle did push back its middle and high school starting times beginning in the 2016-2017 school year, from 7:50 a.m. to 8:45 a.m.

A study published today confirms the delay start is paying off. As NPR reports today under a "Sleepless No More In Seattle" headline:

Researchers at the University of Washington studied the high school students both before and after the start-time change. Their findings appear in a study published Wednesday in the journal Science Advances. They found students got 34 minutes more sleep on average with the later school start time. This boosted their total nightly sleep from 6 hours and 50 minutes to 7 hours and 24 minutes.

"This study shows a significant improvement in the sleep duration of students, all by delaying school start times so they're more in line with the natural wake-up times of adolescents," says senior author Horacio de la Iglesia, a University of Washington researcher and professor of biology.

The study also found an improvement in grades and a reduction in tardiness and absences.

The study also shows a link between getting more sleep and better academic performance. Students who took the biology class after the later start time got final grades that were 4.5 percent higher than students who took the class when it started earlier. That could be the difference between an A and a B, says de la Iglesia. He says sleep deprivation makes it more difficult to learn and to retain new information.