The amount of time students spend in school is a popular lever of change pulled by education policymakers of all types. Longer days or shorter days ; four-day weeks ; starting school later in the morning; longer years or shorter years . Every permutation has been on the table at one time or another in recent years, with varying success. A study released this spring by Matt Kraft and Sarah Novicoff, and published as an Education Next article last month, takes a look at how much time kids actually spend in school in the U.S. these days. They compare these findings internationally and within U.S. states, while synthesizing what the best studies have to say about time use in education.