I Can't Make You Love Hannah If You Don't - S1-E4
Character mistake: When Olivia turns up at Jackson's house, she says, "That was my Saturday afternoon. This is my Saturday night!" which indicates it is the same day. But when Cooper arrives, he says, "Sorry for blowing off at you yesterday," which means another day has passed. However, at the Hannah concert, it is the same day all the while, so Cooper had got his days wrong.