This is mostly high schools. School buses take two or three rounds in delivering kids to school, starting with high schoolers, then middle schoolers, then elementary schoolers. There is all sorts of variation to be had. Middle schoolers in my neighborhood seem to start school at 9AM or at least after 8:30.
I guess I learn something new every day. So Breakfast at 6? Leave home at 6:30?
I imagine this is because this give enough time for parents to go to work after they dropped their kids?
Thank God we have boarding school in the UK.