A building closure and an available return device

An original Spanish notice says “La biblioteca está cerrada el lunes. El buzón de devolución funciona todo el día. Abrimos el martes a las diez”. A reader wants to return a book on Monday and visit the building on Tuesday. One answer treats the building’s closure as proof that no return service exists. Another moves Tuesday’s opening time to Monday. The task asks the learner to distinguish the service, the building and the two days from the actual words. It is fictional language practice, not a real institution’s current notice. The text supplies no Sunday schedule, loan-extension promise or reserved-book availability. The learner should not add a fee rule, a closing hour or a general law about library access. The purpose is a faithful interpretation of a specific supplied standard-Spanish context.