For context, the national picture shows wide variation. K-12 public schools in the United States operate on average just under seven hours a day for about 179 days a year, totaling roughly 1,200 hours of instruction, according to a Brown University and Stanford University analysis of more than 70 studies. [1] Students who attend schools in the top 10% for total time in session receive, on average, five more weeks of instruction each year than those in the lowest 10% — a gap that compounds over a student’s entire academic career. [1]
“It’s really important to recognize that time matters, but we need to use it well,” said Matthew Kraft, an associate professor of education and economics at Brown University, who co-authored the analysis. “There are likely diminishing returns. If you have a superlong school day, adding a little bit more time probably doesn’t get you as much (effective learning time) as adding an extra day to the calendar if it’s a short calendar year.” [1]