California Code, Public Utilities Code - PUC § 1733

(a) Any application for a rehearing made 10 days or more before the effective date of the order as to which a rehearing is sought, shall be either granted or denied before the effective date, or the order shall stand suspended until the application is granted or denied;  but, absent further order of the commission, the order shall not stand so suspended for more than 60 days after the date of filing of the application, at which time the suspension shall lapse, the order shall become effective, and the application may be taken by the party making it to be denied.

(b) Any application for a rehearing made within less than 10 days before the effective date of the order as to which a rehearing is sought, and not granted within 60 days, may be taken by the party making the application to be denied, unless the effective date of the order is extended for the period of the pendency of the application.