What does "Dog Days" mean ?

I know it maybe so late, as the song "Dog Days are over" was originally released 2 years before... but I listened to it on Glee, and Loved its both versions... but can't get a satisfying meaning for the expression "Dog Days", some people mentioned its madness, and others said something... show more I know it maybe so late, as the song "Dog Days are over" was originally released 2 years before... but I listened to it on Glee, and Loved its both versions... but can't get a satisfying meaning for the expression "Dog Days", some people mentioned its madness, and others said something else... any help ?!
7 answers 7