Q: A dog day as I understand it, in reference to the learned one. Sirius was accused of a crime he didn't commit, as punishment the pup was sent to earth to dig up the dirt. So the reference of a dog day afternoon, is simply this, the day started out okay, but by days end it was a mess. Everything that could go wrong went wrong, what a dog day afternoon it was.
A: My understanding are that the Dog Days are in August and it was when it is so hot that it was really tough on the dogs. ~