R.I. Gen. Laws § 28-9.2-13

Whenever wages, rates of pay, or any other matter requiring appropriation of money by any city or town are included as matter of collective bargaining conducted under the provisions of this chapter, it is the obligation of the bargaining agent to serve written notice of request for collective bargaining on the corporate authorities at least one hundred twenty (120) days before the last day on which money can be appropriated by the city or town to cover the contract period which is the subject of the collective bargaining procedure.