Cal. Welf. and Inst. Code § 5254
The person delivering the copy of the notice of certification to the person certified shall, at the time of delivery, inform the person certified that he or she is entitled to a certification review hearing, to be held within four days of the date on which the person is certified for a period of intensive treatment in accordance with Section 5256 unless judicial review is requested, to determine whether or not probable cause exists to detain the person for intensive treatment related to the mental disorder or impairment by chronic alcoholism. The person certified shall be informed of his or her rights with respect to the hearing, including the right to the assistance of another person to prepare for the hearing or to answer other questions and concerns regarding his or her involuntary detention or both.
Ca. Welf. and Inst. Code § 5254