A library notice and an unstated schedule

An original Basque practice notice reads: “Liburutegia astelehenean itxita egongo da. Asteartean irekiko da”. One learner reports that the library will be open on Monday because both days are mentioned in the same notice. Another invents a Sunday schedule, although Sunday does not appear. A third distinguishes Monday’s closure from Tuesday’s opening and leaves the unmentioned day unknown. The task asks for the information explicitly established and the limits of inference. No real library, exact opening hour, holiday or membership policy is supplied. This is a newly composed classroom exercise, not a quotation from an actual institution or a current official announcement. The answer should follow the Basque wording rather than infer that a familiar building always follows a particular weekly routine.