Nearly everyone is wondering how to start what will be the most uncertain new school year of our lifetimes. I sense both fear and hope. It is going to be a mess, but that may inspire worthy innovations.

Here is my suggestion: For decades, the average American neighborhood school has ignored what appears to be one of the best tools for raising achievement — increased learning time. Why not do something about that? Many celebrated teachers have shown the power of stealing a few hours from lunch or after school. But policymakers remain uninterested.

We have been stuck for decades with just 6½ hours of school a day, five days a week, 180 school days a year. “It is a failure of imagination,” said Chris Gabrieli, one of the nation’s leading advocates for more time. “People are so inured to the system we have had that they cannot imagine just changing the parameters.”

Gabrieli, chairman of the Massachusetts Board of Higher Education and a lecturer at the Harvard Graduate School of Education, has learned to live with his frustrations. He said the lack of sufficient time is wired into our schools in two ways: We have known no other system our whole lives, and teacher contracts in strong union states require that any schedule changes be negotiated.

There are, however, enclaves of extended time that could grow larger out of desperation in the chaos of the coming months. The nonprofit organization Empower Schools, where Gabrieli serves as chief executive, and other activists have designed and launched 10 empowerment zones in Massachusetts, Texas, Colorado and Indiana. In those places, the educators at about 50 schools with 25,000 students decide the schedule, permitting them to choose longer school days and sometimes longer school years.

“Texas also passed important legislation last year that will allow any district in the state to add 30 days to the school year and be reimbursed for half of the normal daily amount,” Gabrieli said.

One suggestion for ensuring enough physical space between students this fall would be to have two shifts, with fewer students in each class. Teachers are more effective if class sizes can be cut below 18 students, research has found. That may also be a way to work more time into the day for each child.

In Massachusetts, advocates successfully argued in some districts for 30 to 33 percent more time, an additional 300 hours a year. That came out to one hour and 40 minutes a day, about two more class periods. “We generally argued for one period of pure personalized support for students on the skills where they needed more support,” Gabrieli said, “and one period of well-rounded education, such as arts and music . . . with some students who really need it having both periods devoted to academic support.”

The Massachusetts time-expansion effort was able to get those extra 300 hours for just $1,300 per student, much less than 30 percent of all costs, despite teachers negotiating increased pay. “More learning time added to the day costs no more lunch food, no more bus rides, no more superintendent and central-office staff time,” Gabrieli said.

The most successful public charter school networks made their reputations with longer school days, leading to higher achievement rates even for the children of low-income parents. School schedules in KIPP, the largest charter network, with 242 schools, vary from region to region but tend toward a school day lasting from 8:20 a.m. to 4 p.m., said KIPP Foundation spokeswoman Maria Alcón-Heraux. That is an hour longer than the national average.

Just how schools could sort out their catastrophic problems this fall and still add more time is anyone’s guess. My idea would be to add each day an hour of quiet reading by students enjoying books they pick themselves. That could be done while teachers sit at their desks preparing future lessons.

If you have suggestions for saving the new school year, send them to me at jay.mathews@washpost.com or post them with the comments on this column online. I will print the best. Those of you who found yourselves — surprise! — working as unpaid instructors the past few months may have something to teach the rest of us.