The Director of Human Resources Management shall assign an anniversary date to each employee upon said employee's initial appointment, promotion, demotion, reemployment, and reappointment to a vacant position in the classified service, or such other date established in the Salary Plan. An employee's anniversary date shall be utilized by the Director of Human Resources Management for purposes of determining the date for the initiation of official performance evaluations, consideration of subsequent merit step rate increases, and for application of credit for years served at the maximum rate for employees who are promoted, demoted, reallocated, displaced, reclassified, or transferred to a vacant position in the classified service.