N.Y.C. Charter § 39: Section 39. Reconsideration.

At any time prior to the election at which a local law is to be submitted to the electors for approval pursuant to this charter, the council, not later than fifteen days prior to the election, may reconsider its action thereon and repeal such local law without submission to the mayor, whereupon the proposition for its approval shall not be submitted at such election, or if submitted the vote of the electors thereon shall be without effect.