Subject to the exceptions provided or permitted by law, the taxable status of persons and property shall be determined as of the first day of January or such other date as may subsequently be required by law, which shall be deemed the tax day. Values on the assessment roll shall be determined according to the facts existing on the tax day for the year for which such roll is made and no change of the status or of the location of any such property after that day shall be considered by the Assessor or the Board of Review.