The board of commissioners provided for by this part shall hold regular public meetings on the first and third Tuesdays of each month at some regular hour to be fixed by the board from time to time, and publicly announced by it; provided, however, that the board may by ordinance provide that it shall hold regular public meetings on Tuesday of each week, or on the second and fourth Tuesdays of each month, the time of such meetings to be fixed by the board from time to time and publicly announced by it; and the board may hold such adjourned, called, and other meetings as may be necessary or convenient.