The taxable status of property shall be determined as of the first day of January, or such other as may subsequently be required by the law, which shall be the assessment day. Values on the assessment roll shall be determined according to the facts existing on the assessment day for the year for which the assessment roll is made, and no change of the status of any property after that day shall be considered by the Council when acting as a board of equalization. Standards of appraisal shall be followed by the Council when established as a board of equalization. Standards of appraisal shall be followed by the Council when established by law.