California Code, Education Code - EDC § 45127

(a) The workweek of a classified employee, as defined in Section 45103 or 45256, shall be 40 hours. The workday shall be eight hours. These provisions do not restrict the extension of a regular workday or workweek on an overtime basis if it is necessary to carry on the business of the district.This section does not bar the district from establishing a workday of less than eight hours or a workweek of less than 40 hours for all or any of its classified positions.

(b) Notwithstanding this section and Section 45128, a governing board may, with the approval of the personnel commission, where applicable, exempt specific classes of positions from compensation for overtime in excess of eight hours in one day, provided that hours worked in excess of 40 in a calendar week shall be compensated on an overtime basis.This exemption applies only to those classes that the governing board and personnel commission, where applicable, specifically find to be subject to fluctuations in daily working hours not susceptible to administrative control, such as security patrol and recreation classes, but shall not include food service and transportation classes.

(c) This section applies 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).