Promotion Step Credit. Effective July 1, 1987, employees who lose step credit as a result of promotion shall earn step credit at the rate of two steps of credit for each year of service until the step credit is equal to the years of service or until they reach the first year on the longevity schedule, whichever comes first. When the employee reaches the longevity step as the result of the two steps of credit for each year of service the longevity increment will be awarded again.