Best predictive algorithm on gym classes [closed]

I am working on a predictive feature in a website (academic assignment) I build myself. If the gym classes are on Friday, Saturday and Sunday, how do I predict whether the student will come on the next Friday, Saturday and Sunday, based on the existing history attendance record of that student? Are there any other external variables to consider? (e.g. exam season) Is it possible to predict the whether the student will come on every Friday, Saturday and Sunday of the next month based on the existing records?