California Code, Education Code - EDC § 87414

Every contract or regular employee employed after June 30, 1947, shall be deemed to have been employed on the date upon which he or she first rendered paid service in a probationary or contract position.

Every academic employee who first rendered paid service on the same date shall participate in a single drawing to determine the order of employment, except that in community college districts having a full-time equivalent student in excess of 15,000, an independent auditing firm may be employed to assign to those employees numbers at random which shall determine the order of employment.  Any determination of an employee's order of employment pursuant to this section shall be made within 30 days of the date service was first rendered by the employee.