Apparently, there are some folks who are trying to game this country’s educational system:
[Starting the school year earlier] is a way to game the system of measuring student achievement through standardized tests. Deceptive educators and sleazy school boards want to make their students look better on tests without actually teaching them better. They figure that by moving the school year up, their students can benefit from more classroom instruction before taking the tests, thereby giving them slightly higher grades compared to students who start school at the normal time.
Unfortunately, that sounds entirely logical. Now, if the children actually ended up learning more overall as a result of this, that might be something worth emulating.