Case C-439/23, Consiglio nazionale delle Ricerche: Judgment of the Court (Sixth Chamber) of 19 September 2024 (request for a preliminary ruling from the Tribunale civile di Padova – Italy) – KV v Consiglio nazionale delle Ricerche (CNR) (Reference for a preliminary ruling – Social policy – Directive 1999/70/EC – Framework agreement on fixed-term work concluded by ETUC, UNICE and CEEP – Clause 4 – Principle of non-discrimination – Recruitment of a fixed-term worker as a permanent worker – Determination of length of service – Failure to take into account periods of employment completed under fixed-term employment contracts concluded before the expiry of the deadline for the transposition of Directive 1999/70 – Immediate application to the future effects of a situation which arose under the old rule)