Overheard Conversation No. 27

(A group of people in a car on the motorway. Heavy traffic.)
Girl A: "It's 5 o' clock though, it's rush hour int it?"
Girl B: "Yeah, but it's Sunday."
Girl A: ... (puzzled expression)
Girl B: "There's no rush hour on Sunday."
Girl A: (Still puzzled.) "Is there not?... But some people still go to work."