American students generally spend about 180 days in school each school year. But districts around the country, including those in Arizona, have been playing with the calendar a bit to change how those 180 days are spread out.

The National Center on Time and Learning studies this kind of thing. It issues a report every other year on the subject and the most recent one came out this week. Jennifer Davis is the group’s co-founder and president.

There is a law allowing schools to add 20 days to their calendars, but it only provides a 5 percent funding increase to do it. For more on this, we turn to Tracey Benson, associate executive director of the Arizona School Boards Association.