Employers cannot alter the total hours outlined in your contract without your explicit agreement. However, they can adjust the distribution of those hours. For instance, if your standard shift is 9 a.m. to 6 p.m. (8 hours), they may shift it to 8 a.m. to 5 p.m. Refusing such a reasonable change could lead to dismissal for misconduct.
Schedule changes must not intentionally harm you and require a legitimate reason, such as updated supplier delivery times. Employers need your consent for shifts from continuous (e.g., 9 a.m. to 6 p.m.) to discontinuous schedules (e.g., 9 a.m. to noon, then 4 p.m. to 9 p.m.), weekend work if not previously required, or day-to-night shifts—unless night work is inherent to the role (e.g., gas stations, clinics). For part-time contracts, no changes are allowed without agreement.
Insights from Maître Julien Boutiron, labor lawyer and author of "Labour Law For Dummies" (Ed. First).
