Scheduling of Rest and Meal Periods. The rest and meal periods will be scheduled by the supervisor. Rest periods, to the extent practicable, will be scheduled during the middle two (2) hours of each half shift, as long as such half shift is at least three (3) hours in duration. Such rest breaks may not be scheduled immediately before or after the meal period or at the start or end of a shift. Meal periods, except with express supervisory approval and for infrequent and unusual circumstances, shall not be scheduled at the first or last hour of the work day. Employees shall promptly be at the appropriate work station or area performing their assigned tasks immediately preceding and following each meal and/or rest period.