All bills to customers of the electric utility shall be rendered and due monthly. If not paid by the fifteenth day following the date of the bill, there shall be added 10% of the first $3 of the bill plus 3% of the amount of the bill in excess of $3. Remittances sent by mail on or previous to the fifteenth day as evidenced by the U.S. Post Office mark on the envelope in which they are received will be accepted as within the time limit. When the fifteenth day is a Sunday or other legal holiday, the first business day thereafter shall be considered within the time limit. Bills are payable at the office of the Clerk-Treasurer in the Town Hall building.
('83 Code, § 4-1 II.)