Cal. Education Code § 45133

(a) Notwithstanding Sections 45127 and 45131, a governing board of a school district or a county superintendent of schools may establish a 9-hour-per-day, 80-hour-per-2-week work schedule, provided the establishment of the work schedule has the concurrence of the employee organization, or in the absence of an employee organization, the concurrence of the affected employee. (b) When a 9-hour-per-day, 80-hour-per-2-week work schedule is established, it shall consist of nine work days, eight of which shall be nine-hour days, and one of which shall be an eight-hour day. The overtime rate shall be paid for all hours worked in excess of the required work day, which shall not exceed nine hours, at a rate equal to one and one-half times the regular rate of pay for the employee designated and authorized to perform the work. (c) When a 9-hour-per-day, 80-hour-per-2-week work schedule is established, the workweek shall be defined in either of two ways, as follows: (1) The workweek shall begin on noon Friday and will end at noon the following Friday, with the employee working nine hours each day except on alternate Thursdays when the employee will work eight hours, and on alternate Fridays when the employee will not work; or, (2) The workweek shall begin at noon on any other day of the week and shall be defined so that no employee will be required to work more than 40 hours during any given workweek. (d) This section shall apply to districts that have adopted the merit system in the same manner and effect as if it were a part of Article 6 (commencing with Section 45240) of this chapter.