The effective date of a position reclassification or acting capacity pay designation shall be the date on which the duties and responsibilities warranting the reclassification or acting capacity pay designation are assigned to the position, but the effective date may not be earlier than 1 year before the date on which the reclassification or acting capacity pay designation is authorized or within 1 year of the date when the employee's grievance concerning reclassification or acting capacity pay designation was filed. Back pay awarded as the result of a reclassification or acting capacity pay designation grievance shall be in accordance with State Personnel and Pensions Article, §12-402, Annotated Code of Maryland. A position reclassification or acting capacity pay designation which is the result of the adoption by the Secretary of a new or revised classification title or new or revised standards shall be effective on the date determined by the Secretary.