California Code, Education Code - EDC § 44048

A classified school employee currently employed by any school district or a county superintendent of schools which decides to maintain classes on Saturday or Sunday, or both, shall not, without his or her written consent, be required to change his or her workweek to include Saturday or Sunday, or both.  No such classified employee shall be assigned to perform services on a Saturday or Sunday if such classified employee objects in writing that such assignment would conflict with his or her religious beliefs or practices.  Enactment of this section shall cause no change or disruption in existing work schedules which may already include Saturday or Sunday as regular workdays.

This section shall not be construed as limiting the power of any governing board of a school district, or a county superintendent of schools, to govern the schools of the district, including the assignment of classified employees employed by such district or county superintendent of schools.

This section shall not be construed as modifying or otherwise affecting in any way the provisions of Sections 45127, 45128, or 45131, or any other provisions of this code relating to employment of classified employees.