The amount to be apportioned to a qualifying school in any current year shall be paid in two equal installments, the first to be made on or before January fifteenth and the other not later than June fifteenth of such year, except that for the school year commencing July first, nineteen hundred seventy-one such apportionment shall be made in one payment on or before June fifteenth, nineteen hundred seventy-two. The commissioner may provide for later payments for the purpose of adjusting and correcting apportionments. The amount to be apportioned to a qualifying school shall be payable on order and warrant of the comptroller on vouchers certified or approved by the commissioner in the manner provided by law.