Section 173.1 — Canada Labour Code: Shift changes

If an employer changes a period or shift during which an employee is due to work or adds another work period or shift to the employee’s schedule, the employer shall give the employee written notice of the change or addition at least 24 hours before in the case of a change, the employee’s original work period or shift is to begin or, if the work period or shift that results from the change is to begin earlier than the original work period or shift, before the period or shift that results from the change is to begin;

and in the case of an addition, the work period or shift that was added is to begin. Subsection (1) does not apply if the change to or addition of a work period or shift is necessary to deal with a situation that the employer could not have reasonably foreseen and that presents or could reasonably be expected to present an imminent or serious threat to the life, health or safety of any person; threat of damage to or loss of property; or threat of serious interference with the ordinary working of the employer’s industrial establishment. Subsection (1) does not apply to a change to or addition of a work period or shift following a request made under subsection 177.1(1).