In case the adoption of the budget resolution is delayed until after July 1, the board of education shall make interim appropriations for the purpose of paying salaries and the usual ordinary expenses of the local school administrative unit for the interval between the beginning of the fiscal year and the adoption of the budget resolution. Interim appropriations so made and expended shall be charged to the proper appropriations in the budget resolution. (1975, c. 437, s. 1; 1981, c. 423, s. 1.)