California Code, Code of Civil Procedure - CCP § 12a

(a) If the last day for the performance of any act provided or required by law to be performed within a specified period of time is a holiday, then that period is hereby extended to and including the next day that is not a holiday. For purposes of this section, “holiday” means all day on Saturdays, all holidays specified in Section 135 and, to the extent provided in Section 12b, all days that by terms of Section 12b are required to be considered as holidays.

(b) This section applies to Sections 659, 659a, and 921, and to all other provisions of law providing or requiring an act to be performed on a particular day or within a specified period of time, whether expressed in this or any other code or statute, ordinance, rule, or regulation.