Section 1217 - General transitional provisions(a) For the purposes of any local law, ordinance or resolution imposing a local tax pursuant to the authority of section twelve hundred ten, twelve hundred eleven, twelve hundred twelve or twelve hundred twelve-A or increasing the rate of such tax, all references in section eleven hundred six to August first, nineteen hundred sixty-five shall be read as referring to the effective date of such local law, ordinance or resolution, all references in said section to April first, nineteen hundred sixty-five shall be read as referring to a date four months prior to the effective date of such local law, ordinance or resolution and the reference in subdivision (b) of section eleven hundred six to July thirty-first, nineteen hundred sixty-five shall be read as referring to the day immediately before the effective date of such local law, ordinance or resolution.(b) In applying the provisions of section eleven hundred nineteen with respect to pre-existing lump sum or unit price construction contracts to a tax on retail sales of tangible personal property or a compensating use tax imposed pursuant to the authority of section twelve hundred ten or twelve hundred eleven, all references in said section to the date of the enactment of article twenty-eight or the enactment of a law increasing the rate of tax imposed under said article shall be read as referring to the date of the enactment of the local law, ordinance or resolution imposing such local tax or increasing the rate thereof.