(a) The head of each installation or activity in a wage area shall place new or revised wage schedules into effect at the beginning of the first full shift on the date specified on the schedule by the lead agency.

(b) No agency may retroactively change any personnel or pay actions taken between the effective date of a new or revised wage schedule and the date it is actually put into effect if the personnel or pay actions taken during this period of time are more advantageous to an employee than the same personnel or pay action would have been had the new or revised wage schedule been placed into effect on the date specified by the lead agency.

(c) In applying a new or revised wage schedule, the scheduled rate of pay of an employee paid at one of the steps of the employee's grade on an old wage schedule shall be adjusted upward to the newly adjusted rate for the same numerical step of the grade whenever there is an increase in rates. Except when there is a decrease in wage rates because of a statutory reduction in scheduled rates, the employee is entitled to pay retention as provided in 5 CFR 536.301(a)(8).