Cal. Gov. Code § 31641.95
Sections 31470.7, 31478, 31479, 31480, 31641.1, 31641.2, 31641.3, 31641.4, 31641.8, and 31641.9 may only be applicable in any county or district on the first day of the month after the governing board of such county or district adopts, by majority vote, a resolution providing that those sections shall become applicable in such county or district. Such resolution may limit the applicability of such sections to any one or more of the public agencies as defined by Section 31478.
At any time after such a resolution has been adopted, the governing board of the county or district, by majority vote, may adopt a further resolution declaring that from and after a future date stated further in the resolution, the benefits of the resolution described in the first paragraph of this section shall not be available to any employees who are hired by the county or district after that date.
Ca. Gov. Code § 31641.95