California Code, Education Code - EDC § 22509

(a) Within 10 working days of the date of hire of an employee who has the right to make an election pursuant to Section 22508 or 22508.5, the employer shall inform the employee of the right to make an election and shall make available to the employee written information provided by each retirement system concerning the benefits provided under that retirement system to assist the employee in making an election.

(b) Any election made pursuant to subdivision (a) of Section 22508 or subdivision (a) of Section 22508.5 shall be made in writing on a properly executed form prescribed by the system within 60 calendar days from the date of hire in the position requiring membership in the other public retirement system and shall be received at the system's headquarters office within 60 calendar days after the date of the employee's signature. The employer shall retain a copy of the employee's signed election form and submit the original signed election form to the system's headquarters office.

(c) Any election made pursuant to subdivision (c) of Section 22508 or subdivision (b) of Section 22508.5 shall be filed with the office of the Public Employees' Retirement System.

(d) Any election made pursuant to Section 22508 or Section 22508.5 shall become effective as of the first day of employment in the position that qualified the employee to make an election.