After the first reading of the adopting ordinance and of the code to be adopted thereby, and of any secondary codes therein adopted by reference, the governing body shall schedule a public hearing thereon. Notice of the hearing shall be published twice in a newspaper of general circulation in the adopting county, once at least fifteen days preceding the hearing and once at least eight days preceding it. If there is no such newspaper, the notice shall be posted in the same manner as provided for the posting of a proposed ordinance. The notice shall state the time and place of the hearing. It shall also state that copies of the primary code and also copies of the secondary codes, if any, being considered for adoption are on file with the county clerk and recorder and are open to public inspection. The notice shall also contain a description which the governing body deems sufficient to give notice to interested persons of the purpose of the code and of any secondary code incorporated therein by reference, the subject matter of each such code, the name and address of the agency by which each has been promulgated, or, if a municipality or county, the corporate name of such municipality or county which has enacted such code, and the date of publication of such code or codes, and in the case of a code of any municipality or county the notice shall contain specific reference to code or codes of a given municipality or county as they existed and were effective at a given date.