California Code, Public Resources Code - PRC § 7954

Upon the filing of the petition, the court shall set a day for the hearing thereof not less than 20 days from the date of the filing of the petition.  A copy of the petition and of the order fixing time of hearing shall be served upon all owners of lands which are or may be affected by the decree of confirmation at least 10 days before the hearing and such owners may appear upon the day fixed and oppose the petition.