The right to take an annual period of paid leave is a right of constitutional rank according to Article 36 paragraph 3, of the Italian Constitution, which provides that “the worker has right […] to an annual period of paid leave, and he cannot renounce it”.
On the other hand, Article 2109 Italian Civil Code is also concerned with the institution of holidays: “The employee has […] also right […] to an annual period of paid leave, if possible continuous, in the time that the employer establishes, taking into account the needs of the company and the interests of the employee. The duration of this period shall be determined by law, custom or equity. The employer must inform in advance the employee with reference to the period of the holidays. The notice period provided with Article 2118 may not be counted in the annual paid leave”.
Source: full italian version published by Guida al lavoro – Il Sole 24 ore.