As Labor Day creeps closer, many Americans may reminisce about a time when they would return to school following the long weekend that traditionally marks the informal end of summer. But across the country, the vast majority of public school students are already back in the classroom. An MDR Education report found that about 84% of public schools began in August this school year, and nearly half of those began prior to Aug. 16.

The historic deciding factor for start times? Labor Day. Start beforehand, and face greater facilities costs cooling schools on hot summer days, as well as the possibility of running afoul of family vacations, summer jobs, camp schedules and teacher preparation. Start after, and educators argue that students lose important learning opportunities.

The nationwide practice of starting school schedules after Labor Day was much more common just a few decades ago. It wasn’t until the mid-1990s that August start times picked up in popularity. Now, they seem inescapable, with just a few states still maintaining the now-controversial mandate to start after the September holiday. But why?

Start Times Get Political
In some states, the push to start school earlier has a messy history. According to 2023 data from the Education Commission of the States, just 15 states still hold statewide mandates for school start or end dates. School districts and educators are often wary of statewide laws, as they can’t take into account the specific needs and factors of each school.