Cal. Welf. and Inst. Code § 637
When a hearing is held under the provisions of this article and no parent or guardian of such minor is present and no parent or guardian has had actual notice of the hearing, a parent or guardian of such minor may file his affidavit setting forth such facts with the clerk of the juvenile court and the clerk shall immediately set the matter for rehearing at a time within 24 hours, excluding Sundays and nonjudicial days from the filing of the affidavit. Upon the rehearing, the court shall proceed in the same manner as upon the original hearing.
If the minor or, if the minor is represented by an attorney, the minor's attorney, requests evidence of the prima facie case, a rehearing shall be held within three judicial days to consider evidence of the prima facie case. If the prima facie case is not established, the minor shall be released from detention.
When the court ascertains that the rehearing cannot be held within three judicial days because of the unavailability of a witness, a reasonable continuance may be granted for a period not to exceed five judicial days.
Ca. Welf. and Inst. Code § 637