General Revision of Assessments.
Section 21
SEC. 21. General Revision of Assessments.—Beginning with the calendar year 1978, the provincial or city assessor shall make a general revision of real property assessments in the province or city to take effect January 1, 1979 and once every five years thereafter: Provided, however. That if property values in a province or city, or in any municipality, have greatly changed since the last general revision, the provincial or city assessor may, with the approval of the Secretary of Finance or upon his direction, undertake a general revision of assessments in the province or city, or in any municipality before the fifth year from the effectivity of the last general revision.