Hey, Mom! It's Monday, but how do we know it's Monday? What I mean is that way back in the ancient past, days didn't have names. Then someone decided to give 'em names. Well, what if that person got it wrong? What if the day he called Monday was really Thursday, only he didn't know it was Thursday 'cause it didn't yet have a name? That would mean everybody's been taking the wrong days off from work for, like, ages.