If an employee has been receiving pay for work out of class as provided in this MOU or in the Salary Ordinance for thirty (30) or more calendar days immediately preceding a paid holiday, the commencement of a vacation, the commencement of a paid sick leave period, or compensatory time off, as the case may be, the work out of class pay shall be included in such employee’s holiday pay, vacation pay, paid sick leave or paid compensatory time.