September 1st and 2nd

It just occurred to me, if the Hogwarts train always left on September first, and classes always started on September 2nd, then classes couldn't have always been Monday thru Friday, because September 1st doesn't always fall on a Sunday, so what happened when it fell on a Friday, did classes start on a Saturday, or did J.K. Rowling miss this.... --BachLynn^(Accio!) 18:48, September 23, 2010 (UTC)