The City Council may, from time to time on its own motion, on petition, or on recommendation of any board, agency, or official of the City, and after public notice and hearing as required by law, act to amend, supplement, repeal or change the regulations and districts established under this chapter.

Where petition is made by the owners of 50% or more of the frontage in any district or of the frontage of the several properties constituting a part thereof, as provided by § 83 of the General City Law, the City Council shall hear and vote upon said petition within 90 days of the filing of such petition, in proper form, with the City Clerk. In the case of all other applications and petitions submitted to the City requesting an amendment of this chapter, the City Council may, on its own motion, decide not to formally consider such amendment.

If any amendment is to be considered by the City Council, it shall be referred for review and report to the Planning Board, the Corporation Counsel, and any other board, agency or official of the City which the City Council deems appropriate. The Planning Board may confer with the petitioner and assist such petitioner, where appropriate, to place the amendment in its most suitable form. Such conference and assistance shall not be deemed to constitute any commitment by the Planning Board as to its position on the advisability of the proposed amendment nor to require the petitioner to make any modification to his application. After said conference, however, the petitioner shall be allowed to revise his petition and to provide copies of such revised petition to the City Council and to any board, agency or official to which the original proposed amendment was referred. The Corporation Counsel shall report to the City Council regarding the form of the proposed amendment. The Planning Board shall report to the City Council regarding the form and the advisability of the proposed amendment. Its report shall analyze the proposed amendment and shall state the Board's reasons for its recommendation, describing any conditions it believes make the amendment advisable or not, and specifically stating whether the amendment would be in accordance with the purposes of this chapter as set forth in Article I. All boards, agencies and officials to which such proposed amendments are referred shall have not less than 30 days from the date of forwarding, or from the date of revision by the petitioner, whichever is later, to submit their reports. In no case shall this article restrict the right of an applicant to come before the Planning Board for an informal discussion and review prior to formal submission of a petition for amendment of this chapter.

On receipt of the requested reports and any revised proposed amendment from an applicant or notification by the applicant that no revision will be made, the City Council may schedule and hold a public hearing on the proposed amendment.

The City Clerk shall forward copies of the proposed amendment with the notice of public hearing to the Westchester County Planning Board and to the clerks of any abutting municipalities as required by law.

The action of the City Council to approve any proposed amendment to this chapter shall be by majority vote, except, however, if a protest is presented against such amendment, duly signed and acknowledged by the owners of 20% or more of the area of any land included in such proposed change, or by the owners of 20% or more of the area of the land immediately adjacent and extending 100 feet therefrom, or by the owners of 20% or more of the area of land directly opposite thereto extending 100 feet from the street frontage of such opposite land, such amendment shall not be passed except by a three-fourths-vote of the City Council.

The City Clerk shall keep the official record copy of the Zoning Map and text sections, and shall be responsible for the posting of all changes thereto. The City Clerk and the Commissioner of Development shall also maintain a file of all such zoning maps and text sections which have been superseded by amendment of this chapter.