Joined Cases C-529/21 to C-536/21 and C-732/21 to C-738/21, Glavna direktsia ‘Pozharna bezopasnost i zashtita na naselenieto’ (Night work) and Others: Judgment of the Court (Sixth Chamber) of 4 May 2023 (requests for a preliminary ruling from the Rayonen sad — Kula — Bulgaria) — OP (C-529/21), MN (C-530/21), KL (C-531/21), IJ (C-532/21), GH (C-533/21), EF (C-534/21), CD (C-535/21), AB (C-536/21), AB (C-732/21), BC (C-733/21), CD (C-734/21), DE (C-735/21), EF (C-736/21), FG (C-737/21), GH (C-738/21) v Glavna direktsia ‘Pozharna bezopasnost i zashtita na naselenieto’ kam Ministerstvo na vatreshnite raboti (Reference for a preliminary ruling — Social policy — Organisation of working time — Directive 2003/88/EC — Article 1(3) — Scope — Article 8 — Article 12 — Health and safety of night workers at work — Level of protection for night workers appropriate to the nature of their work — Directive 89/391/EEC — Article 2 — Public sector workers and private sector workers — Article 20 of the Charter of Fundamental Rights of the European Union — Equal treatment)