California Code, Government Code - GOV § 9356.3

(a) If the member is elected as a Member of the Legislature at a special election held prior to June 15 of any calendar year, the period of service of the member during the remainder of that calendar year shall constitute one calendar year of service for the purpose of computing service under this act if he or she makes contributions therefor to the Legislators' Retirement Fund.  Those contributions shall be in an amount equal to that which he or she would have made if he or she had served as a legislator during the period of the calendar year prior to his or her election.

(b) If the time of service of a member elected to fill an unexpired term of office as Member of the Legislature amounts to more than one-half of the full term for that office, he or she shall receive credit for service for the full term of office if he or she makes contributions therefor to the Legislators' Retirement Fund.  Those contributions shall be in an amount equal to that which he or she would have made if he or she had served as a legislator during the remainder of the term.