Do your homework a week in advance. Wait to turn it in (by e-mail). Have snow days. Forget to turn it in. Turn it in an hour late (or at least I thought an hour late). Then get one email from professor stating it is 6 hours late (even though I thought it was only an hour late), and then get a second email ‘to be clear’ he is neither accepting nor reading it.
Moral of the story: do not do homework early.