When you enroll, you are assigned a Piano di Studio called statutory, corresponding to the Regulations of Advanced Molecular Sciences.
The statutory “Piano di Studio” alone is not sufficient to complete your course and graduate: you must present a Piano di Studi, where you will indicate all the exams, including those of choice, to reach 120 CFU required for the master's degree. There are two specific periods of each Academic Year in which it is possible to modify the “Piano di Studio”.

First Period (Primo periodo): generally, from October to November
Second Period (Secondo periodo): generally, from March to April  

More info at SMFN web site link