Whenever in this chapter the rights of a member, because of membership in another retirement system, are conditioned upon reemployment within six months of termination of membership in a system under this chapter or another retirement system, such period shall be one year rather than six months if the member was an elective officer and becomes a member of a system established under this chapter upon commencement of service in another elective office on and after January 1, 1977.

This section shall not be applicable in any county until adopted by the board of supervisors nor until the other employer in a reciprocal system elects a similar provision.