The parties may agree to waive any time limitations specified in this title. If the individual responsible to prepare a decision to a grievance at Step One or Step Two of the grievance procedure cannot respond within the time specified in this title because the individual is on approved leave for 3 or more days: the period for the decision shall be extended by the number of days of the approved leave, up to a maximum of 14 days; and the grievant shall be notified of the extension of time.