Judgment of the Court (Seventh Chamber) of 7 July 2022.#Ville de Mons and Zone de secours Hainaut - Centre v RM.#Reference for a preliminary ruling – Social policy – Directive 97/81/EC – Framework Agreement on part-time work – Clause 4 – Principle of non-discrimination – Principle of pro rata temporis – Taking into account, for the purposes of calculating the remuneration of a full-time professional firefighter, the length of service for remuneration purposes which he has acquired as a volunteer firefighter, in accordance with the principle of pro rata temporis.#Case C-377/21.