ยง 553. Installments.    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.