When is a library book overdue?

So I busted my behind to get to the Shanghai Library after work yesterday when I realized my book was due on May 5th. The fine is a whopping 40 rmb per day ( roughly $6.00 per day - yikes!).
Took a taxi there as I was not sure of the hours. It took thirty minutes in awful traffic- AND I'm pretty sure the driver took the "scenic" route…….argh!

Got sent from one counter to another counter to another…..just trying to pay my late fine. Finally ended up on the 4th floor- where the book was originally "housed". I was told that the book was not overdue. So, when the due date is May 5th, returning it on May 6th is okay? Very confusing………… Oh well, this covered my cab fare.

Took Metro Line 10 back to my bank and  then to the Foreign Exchange place for U.S. dollars. The limit is $500.00 U.S.Dollars per day.BTW- have you seen the new money???

Old:

The new:

After the runaround at the library, I thought- once again- a communication error. I could only see the bills from behind a glass wall and was just about to protest when she slipped them though the money exchange tunnel. Okay. Perfect. We'll do this again tomorrow……...