Hello, how long is the validity of the library card in Yili Prefecture? The library card of Yili Prefecture is valid for 15 days. There is a clear sign on the bulletin board at the front desk of Yili Library. All books must be registered before they can be checked out. Borrowing requires a library card. The time limit is 15 days. Therefore, the library card of Yili Prefecture is valid for 15 days.