N.Y. Suffolk County Tax Act § 9
The board of education or the trustees of any school district may in the year nineteen hundred and twenty or in any subsequent year, in addition to the amount of the budget and other lawful taxes to be raised on the tax roll of said year, include in the total so to be raised an amount not exceeding thirty per centum of such total, which amount shall be known as the contingent fund and shall be applied to the purposes of the budget of the succeeding year in anticipation of the tax to be levied thereon, and in each succeeding year the budget proposed to any school district may provide for the reimbursement of said contingent fund, in such manner that funds to an amount deemed sufficient by the district may be raised and kept available for the expenses of the district between the opening of the school year and the receipt of moneys raised by taxation for such year.
N.Y. Suffolk County Tax Act § 9