25 Pa. Stat. § 2864
To assist the respective county boards in ascertaining the offices to be filled, it shall be the duty of the clerks or secretaries of the various cities, boroughs, towns, townships and school districts, with the advice of their respective solicitors, on or before the thirteenth Tuesday preceding the Municipal primary, to send to the county boards of their respective counties a written notice setting forth all city, borough, town, township and school district offices to be filled in their respective subdivisions at the ensuing municipal election, and for which candidates are to be nominated at the ensuing primary. It shall also be the duty of the chairman of the State committee of each political party to forward to the Secretary of the Commonwealth and to the respective county boards, on or before the thirteenth Tuesday preceding the General primary, a written notice setting forth the number of delegates and alternate delegates to the National convention of such party who are to be elected in the State at large at the ensuing primary, and the number of such delegates and alternate delegates who are to be elected at said primary in such county, or in any district within such county, or of which it forms a part. The said notice shall also set forth the number of members of the National committee, if any, who, under the National party rules, are to be elected at the said primary in the State at large, and the number of members of the State committee to be elected at the said primary in such county, or in any district, or part of a district within such county. It shall also be the duty of the chairman of the county committee and, in cases where a city is coextensive with a county, the chairman of the city committee of each party, on or before the thirteenth Tuesday preceding the General primary, to send to the county board of such county a written notice setting forth all party offices to be filled in the county at the ensuing primary.
25 P.S. § 2864