Why do schools start so early now?

Some schools in the US start in early to mid August now. Back in the day almost all of them started the day after Labor Day (first week in September for those of you who are not American). I know why schools used to all start after Labor Day. Primarily because of the harvest. What I don’t understand is the logic behind starting school in August.

Here in the Memphis area it just makes no sense to me. It must cost more to air condition the schools this time of year compared to having school extend a few weeks later in June? There is a school in a town about 30 minutes from Memphis that does year round, still the same amount of school day though. But, that is another topic.

Some states have reverted back to after labor day after trying it in August. Michigan is one, because they realized starting in August hurt their tourism business. Many Michiganders vacation within the state, and if kids are back in school the family is not travelling. Plus, people who had summer businesses would have to cut their summer short to put their children in school. But, who had the brilliant idea to try starting in August anyway? And, why? There must be some good reasons, because a lot of communities do it now.