I also think elementary school ought to run from 8am to 5 or 6pm, and include multiple rest / free play periods, as well as daily music / art / sports activities (rather than the rotation that gets PE in once or twice a week).
Why should a child spend 9 to 10 hours at school each day? I don't really see the point. We expect adults to put in 8 hour days. Why do you expect more for a child? When would the kids get to play and participate in out of the school activities?
I highly suggest looking at the number of hours kids spend at school in Europe (significantly less than here) and the scores they achieve (significantly more than here). More is sometimes less.
