All new buildings substantially completed or fit for use and occupancy prior to November 1 of the year of completion shall be assessed when so completed or fit for use and occupancy, and the commissioner of the revenue shall enter in the books the fair market value of such building. No partial assessment as provided herein shall become effective until information as to the date and amount of such assessment is recorded in the office of the treasurer and made available for public inspection.
The total tax on any such new building for that year shall be the sum of:
The tax upon the assessment of the completed building, computed according to the ratio which the portion of the year such building is substantially completed or fit for use and occupancy bears to the entire year; and
The tax upon the assessment of such new building as it existed on January 1 of that assessment year, computed according to the ratio which the portion of the year such building was not substantially complete or fit for use and occupancy bears to the entire year.
With respect to any assessment made under this section after September 1 of any year, the penalty for nonpayment by December 5 shall be extended to February 5 of the succeeding year.