California Code, Family Code - FAM § 1836

(a) The court shall fix a reasonable time and place for hearing on the petition.  The court shall cause notice to be given to the respondents of the filing of the petition and of the time and place of the hearing that the court deems necessary.

(b) The court may, when it deems it necessary, issue a citation to a respondent requiring the respondent to appear at the time and place stated in the citation.  The court may require the attendance of witnesses as in other civil cases.