R.I. Gen. Laws § 44-5-13 — Assessment and apportionment according to law — Date of assessment

The assessors shall assess all valuation and apportion any tax levy on the inhabitants
of the city or town and the ratable property in the city or town according to law,
and the assessed valuation of the ratable property shall be made as of the date of
assessment provided in § 44-5-1 and shall be in accordance with the provisions of § 44-5-12; except that personal property consisting of stocks in trade and materials used in
manufacture, which include raw materials, fuel, goods in process of manufacture, and
completed products, except those which are specifically exempt by statute, are estimated
at the average of the personalty kept on hand or located in the taxing district during
the twelve (12) months ending with the date of assessment, or the average of any portion
of the twelve (12) months when the business has not been carried on or located in
the taxing district for a year.