Upon the filing of a request for hearing as provided in Section 30639, the district board shall fix the time and place for hearing. The time fixed shall not be less than 15 days nor more than 60 days from the date the request is filed. Notice of the hearing shall be given to the county or city requesting the hearing, shall be mailed to the governing body of each city and county located, in whole or in part, within the district, and shall be published once by the board.