At least ten days mailed notice of every hearing shall be given to all persons entitled to notice by law, ordinance or resolution, except that published or posted notice may be given where permitted by law, ordinance or resolution. Personal notice may be given in lieu of mailed or published notice, and shall be given when required. The notice shall state the time, place and purpose of the meeting. Failure to give the notice or defects in it shall not invalidate the proceedings if a good faith effort was made to give the notice required, if due to special circumstances giving the notice was impractical or impossible, or if the person not receiving notice or receiving defective notice was not prejudiced thereby.
('82 Code, § 2.212)