Cal. Gov. Code § 20994

Any employee of a contracting agency who is or was absent on military service on the effective date of the contract and who would become or would have become a member if he or she were not absent becomes or became a member on the effective date, with the same status and rights of membership as if he or she were not or had not been so absent on the effective date. Any such employee and any other employee of a contracting agency who was absent on military service prior to the effective date shall receive credit as prior service for time during which he or she was absent on military service prior to the effective date provided the employee is entitled to receive prior service credit pursuant to Section 20933 or 20934 and he or she returned to employment of the contracting agency within six months of the termination of his or her active service with the uniformed services under conditions other than dishonorable or within six months after any period of rehabilitation afforded by the United States government other than a period of rehabilitation for purely educational purposes.