California Code, Code of Civil Procedure - CCP § 630.23

(a) Each side shall have up to five hours in which to complete voir dire and to present its case.

(b) The jury shall be composed of eight jurors and one alternate, unless the parties have agreed to fewer jurors.

(c) Each side shall be limited to four peremptory challenges, unless the court permits an additional challenge in cases with more than two sides. If there are more than two parties in a case and more than two sides, as determined by the court under subdivision (c) of Section 231, the parties may request one additional peremptory challenge each, which is to be granted by the court as the interests of justice may require.

(d) The parties may agree to modify the rules and procedures specified in this chapter and the implementing rules of court, subject to the court's approval.