California Code, Government Code - GOV § 51121

(a) If the board or council after public hearing and by a majority vote of the full body desires in any year not to extend the term of zoning, the county or city shall give written notice of its intent to rezone following procedures established pursuant to subdivision (b) of Section 51113.  A proposed new zone shall be specified.  Unless the written notice is given at least 90 days prior to the anniversary date of the initial zoning, the zoning term shall be deemed extended.

(b) Upon receipt by the owner of a notice of intent to rezone from the county or city, the owner may make written protest of the notice and may appeal to the board or council within 30 days of notice from the county or city.  The board or council may at any time prior to the anniversary date withdraw the notice of intent to rezone.

(c) The board or council shall hold a public hearing on the proposed change and by a majority vote of the full body may reaffirm its intent to change the zoning and specify a new zone.

(d) A new zone of a parcel shall be effective 10 years from the date of the reaffirmation vote pursuant to subdivision (c).  Upon rezoning the parcel shall be valued pursuant to Section 426 of the Revenue and Taxation Code.