(a) A person who smokes a pipe, cigar, or cigarette in a mill, factory, barn, stable, or other outbuilding belonging to or occupied by another person, or in a public building in which a notice containing this section, prohibiting such smoking, signed by the owner, agent, occupant, or custodian of the same is posted conspicuously near the main entrance thereof, shall be fined not more than $5.00.(b) All prosecutions under this section shall be commenced within 30 days from the date of the offense.