How would you like an extra hour of nightly sleep, even on weekdays? For years, scientists have studied the effects of pushing back the morning school bell. A delayed-start experiment in December’s Science Advances reveals that students who catch more Z’s make more A’s.

A good night’s sleep is one of God’s great gifts. But most teens don’t snooze the recommended nine hours. They live like night-owls for a variety of reasons. One is their changing body clocks. God created sleep/wake cycles and internal sensors to postpone sleepiness as humans age. That allows teens to stay awake longer as they prepare for adulthood.

Teens also have increasing academic and social commitments—like soccer, debate, and friend group get-togethers—that occupy them into the evening hours. Of course, social media too can keep many teens (and adults) posting and chatting long after dark.

Sleep researchers wanted to know: Would teenage students sleep longer if school started later? Or would they simply stay up longer?

During the 2016-17 school year, researchers were able to experiment in Seattle. Schools there planned to adopt a later start time—moving from 7:50 a.m. to 8:45 a.m.

For the study, teachers helped recruit 178 sophomores at two schools. The students wore wristwatch-like monitors for two weeks. They also kept diaries about sleep start, waking, napping, moods, and other data.

Student Hazel Ostrowski’s comments reflect her struggle: “I’ll wake up so tired I wish I could go back to sleep. At night, I’ll be on my phone, and I just want to stay up.” But she admits sleeping later made it easier to pay attention during class.

Study results showed the extra hour before school added an average of 34 minutes of slumber per night. It also resulted in less daytime sleepiness and better grades. Researchers say they can’t prove more sleep means straight A’s and B’s. But they call it “reasonable that students who are better rested and more alert should display better academic performance.”

Surprisingly, more sleep resulted in fewer absences and tardies—but only at the school in the poorer area. Researchers suggest delaying school start times “could decrease the learning gap between low and high socioeconomic [income] groups.”

Horacio de la Iglesia led the study. He says, “Given all the pressures keeping our teenagers awake in the evening—screen time, social media—this is a great thing to see.”

More study on the effects of more sleep for teens is needed. But one thing seems certain: You snooze . . . you win.