so until when do I have to return it?

[flytothesky]

Hello~ Can you help me say this naturally please?

A: I was wondering if the book I asked to reserve arrived?


B: Oh, yes, it arrived. Here you are.


A: Oh, thanks,
ⓐso until when do I have to return it?
ⓑSo when is due?
ⓒSo when is due date?

B: You can return it next week on Monday.
ⓐIf you do not return within due,
ⓑIf you do not return within due date,
There will be $1 penalty for every hour.

[abaka]

A: I was wondering if the book I reserved has arrived?


B: Oh yes, it's here. Here you are.


A: Oh, thanks.
(1) So when is it due?
(2) so until when can I check it out?
(3) So when is the due date?
(in order of preference)

B: You can return it next Monday.
If it's late,
There'll be a one dollar penalty for every hour.