Sick Leave Time And The Public School Retirement System. When an eligible Bargaining Unit employee is absent from active duty with the District and uses his/her accrued sick leave time to cover the hours missed from his/her work assignment pursuant to this Article, the District shall continue to make its required contributions to the Public School Retirement System (“PSRS”) on behalf of the employee. The sick leave plan set forth in this Article constitutes the only “sick leave provisions” applicable to any Bargaining Unit employee for purposes of the Missouri Statutes governing the PSRS.