Pay on Calamity. Bargaining unit members shall be paid their appropriate rate of pay for all days or part of a day when schools in which they are employed are closed owing to an epidemic or other public calamity (calamity days), provided that no such employee shall be paid for days of work required to be made up to meet the minimum school year as required by law. Calamity days shall only apply to those positions and classifications which work the first (day) shift unless the Superintendent releases all positions and classifications for more than the first shift.