53 Pa. Stat. § 41418
Except as hereafter provided for submission of the first recommended budget after adoption of the Mayor-Council Plan A, at the last stated meeting in November, the mayor shall submit to council his recommended budget in the form of an ordinance, together with such explanatory comment or statement as he may deem desirable. After adoption of the Mayor-Council Plan A, the first recommended budget together with the explanatory comment or statement, shall be submitted by the mayor in the form of an ordinance to council not later than the first day of March and shall be adopted by council not later than the first meeting in March of the first budget year, or, if the mayor elects to do so, he may recommend the amendment and adoption of the annual budget and the levy of a tax rate under sections 1809, 1810 and 1811 of the act of June 23, 1931 (P.L. 932), known as "The Third Class City Code", reenacted and amended June 28, 1951 (P.L. 662). The budget shall be in such form as is required the council for city budgets, and shall in addition have appended thereto a detailed analysis of the various items of expenditure and revenue. Council may reduce any item or items in the mayor's budget by a vote of a majority of the council, but an increase in any item or items therein shall become effective only upon an affirmative vote of two-thirds of the members of council.
Council shall, upon passing the proposed budget ordinance on first reading, fix a date for adoption thereof, which shall except as otherwise provided be not later than the 31st day of December immediately following.
53 P.S. § 41418