Ever been roused from a deep sleep well before your alarm goes off? If you’re like most people, at that early hour, anything that requires more focus or thought than making coffee can be a struggle.

Now what if you were asked to take a calculus exam, or absorb the finer points of a history lecture?

That’s basically what’s being demanded of many Maine high school students, who because of their biological clocks are still working through pre-dawn cobwebs when the bell rings for first period.

And that’s the case across the country, where too often high school and middle-school students are asked to go to school with so little sleep that it affects their ability to learn, and it can have long-term health consequences.

Backed by a mountain of research, many schools are now rightfully moving back the start of the school day, and schools in Maine, where the average start time is 7:53 and many begin at 7:30 or earlier, should follow suit.

Some already have, and without the disruption and increased costs that opponents insist will occur.

Old Orchard Beach this year moved its high school starting time to 8 a.m. from 7:30, and hope to get to 8:30, the time recommended by both the Centers for Disease Control and Prevention and the American Academy of Pediatrics.

Westbrook, too, has set back its starting time, from 7:30 a.m. to 7:50 in 2012-13, and both communities are bullish on the changes.

Others are looking into it. Earlier this month, officials from 14 southern Maine school districts met to discuss later start times.

That group should help districts move through the objections and show how each can be put to bed, so to speak, because the science behind starting school later is clear.

As any parent will tell you, teens need a lot of sleep. However, according to the AAP, 87 percent of high school students get less than the 81/2 to 91/2 hours of sleep that is recommended.

Lack of sleep stunts cognitive speed as well as the ability to make decisions and retain information, and can hurt academic performance, cut attendance and raise dropout rates.

It also can affect health, causing high blood pressure and obesity, among many other maladies.

And it’s not just a matter of getting to bed early. Because of their body rhythms, teens don’t get tired until later in the day, so just like 7 a.m. for a teen can feel like the middle of the night, 9 p.m. feels like the early evening.

When teens want to stay up, or don’t want to get out of bed, it’s not laziness or insolence, it’s biology.

Some school officials are concerned about how the changes affect bus schedules and after-school activities.

But other schools have figured out how to deal with those issues, and research shows the benefits of later start times far outweigh the costs.

A bill proposed last legislative session would have mandated a statewide 8:30 a.m. start, but it failed, and lawmakers should tread lightly on any law that doesn’t allow school districts to adjust for their own circumstances, including district size and geography.

But all districts that haven’t already should allow teens to start later, and give them a better shot at success each day.