The Parties recognize that changing an employee's posted watch schedule is undesirable. The Agency will normally give no less than seven (7) days notice of its intention to modify a posted watch schedule. In such case, it shall attempt to avoid the change by soliciting qualified volunteers for forty-eight (48 ) hours. If the Agency determines it is necessary to modify a posted watch schedule with less than seven (7) days notice, it will make reasonable efforts to secure qualified volunteers. Changes with less than seven (7) days notice shall not be made for the purpose of avoiding payment of overtime, holiday, or other premium pay. If an employee's shift is involuntarily changed with less than seven (7) days notice, the affected employee shall be paid any night time differentials to which he/she would otherwise have been entitled, had they worked that shift.