California Code, Probate Code - PROB § 17454

(a) At least 30 days before the time set for the hearing on the petition, the petitioner shall cause notice of the time and place of the hearing to be delivered pursuant to Section 1215 to each of the persons named in the petition at their respective addresses as stated in the petition.

(b) Any person interested in the trust, as trustee, beneficiary, or otherwise, may appear and file written grounds in opposition to the petition.