(a) Notwithstanding any other law, the Pacific Unified School District, the Leggett Valley Unified School District, and the Reeds Creek Elementary School District may operate one or more schools in their respective districts on a four-day school week, if the district complies with the instructional time requirements specified in Section 37701 and the other requirements of this chapter. (b) If a school district operates one or more schools on a four-day week pursuant to this section and the program for the school year provides less than the 180 days of instruction required under Section 46200, the Superintendent of Public Instruction shall reduce the base revenue limit per unit of average daily attendance for that fiscal year by the amount the school district would have received for the increase received pursuant to subdivision (a) of Section 46200, as adjusted in fiscal years subsequent to the 1984-85 fiscal year. If a school district operates one or more schools on a four-day school week pursuant to this section and the program provides less than the minimum instructional minutes required under Section 46201, the Superintendent of Public Instruction shall reduce the base revenue limit per unit of average daily attendance for that fiscal year in which the reduction occurs by the amount the school district would have received for the increase in the 1987-88 fiscal year base revenue limit per unit of average daily attendance pursuant to paragraph (6) of subdivision (b) of Section 42238, as adjusted in the 1987-88 fiscal year and fiscal years thereafter. (c) A school district with an exclusive bargaining representative may operate a school on a four-day school week pursuant to this section only if the district and the representative of each bargaining unit of district employees mutually agree to that operation in a memorandum of understanding.