Judgment of the Court (Grand Chamber) of 9 March 2021.#D. J. v Radiotelevizija Slovenija.#Reference for a preliminary ruling – Protection of the safety and health of workers – Organisation of working time – Directive 2003/88/EC – Article 2 – Concept of ‘working time’ – Stand-by time according to a stand-by system – Specific work maintaining television transmitters situated far away from residential areas – Directive 89/391/EEC – Articles 5 and 6 – Psychosocial risks – Obligation to prevent.#Case C-344/19.