California Code, Code of Civil Procedure - CCP § 1277.5

(2)(A) If a proceeding for change of name to conform a minor petitioner's name to their gender identity is commenced by the filing of a petition, and that petition does not include the signatures of all of the minor's living parents, the court shall make an order reciting the filing of the petition, the name of the person by whom it is filed, and the name proposed.

(B) The order shall direct all persons interested in the matter to make known any objection to the change of name by filing a written objection, which includes any reasons for the objection, within six weeks of the making of the order, and shall state that if no objection showing good cause to oppose the name change is timely filed, the court shall, without hearing, enter the order that the change of name is granted after the completion of the six weeks, except as provided in Section 1279.5.

(C) The petition and the order shall be served on any parent who did not sign the petition, pursuant to Section 413.10, 414.10, 415.10, or 415.40, within four weeks from the date on which the order is made by the court.  If service cannot reasonably be accomplished pursuant to Section 415.10 or 415.40, the court may order that service be accomplished in a manner that the court determines is reasonably calculated to give actual notice to the parent who did not sign the petition.

(D) A hearing date shall not be set in the proceeding unless an objection is timely filed and shows good cause for opposing the name change.  Objections based solely on concerns that the proposed change is not the petitioner's actual gender identity or gender assigned at birth shall not constitute good cause.  At the hearing, the court may examine under oath any of the petitioners, remonstrants, or other persons touching the petition or application, and may make an order changing the name or dismissing the petition or application as the court may deem right and proper.