The county court of each county shall hold four regular sessions in each year at the courthouse thereof, at such times as may be fixed upon and entered of record by the court. It may also hold special sessions, whenever the public interests may require it, to be called by the president with the concurrence of at least one other commissioner; and the commissioner, if any, not concurring therein, must have at least twenty-four hours' notice of the time appointed for such special session. A notice of the time of such special session, and of the purpose for which it will be held, shall be posted by the clerk of the court, at the front door of the courthouse of the county, at least two days before such session is to be held. If such commissioner, after due notice thereof, shall willfully fail to attend such special session, he shall forfeit not less than $5 nor more than $20.