All amendments and changes to the official zoning map adopted according to the provisions of this chapter shall be considered a part of this chapter and of the official zoning map at the time of the effective date of all said amendments and changes. The City Council may, from time to time, order revision of the official zoning map so as to include all changes to date. No changes shall be made upon said zoning map which have not been officially adopted according to the provisions of this chapter. The revised map shall become the official zoning map of the city and replace the original map.
('64 Code, § 23.02)