The loan period for books is 28 days (for reading room loans and periodicals 14 days). The loan period can be extended via the catalog (section "My account").
You log in to the catalog plus with your ID number without dots, but with the 0 at the end, and enter your password.
Extensions of the loan period can be made as often as desired, up to a maximum period of 4 x 28 days. Extensions are not possible if someone else needs the book and has entered a reservation via the catalog.
You can see the end of the loan period and any reservations entered in Catalog plus - My account.
If you fail to return a book on or before the due date you have to pay a fine which can be paid in person at the Issue Desk in the main building or via bank transfer.