The governing authority of each municipality and county shall provide for the manner in which the comprehensive plan, zoning ordinance (including the official zoning map) subdivision regulations and capital improvements program shall be determined, established and enforced, and from time to time, amended, supplemented or changed. However, no such plan, ordinance (including zoning boundaries), regulations or program shall become effective until after a public hearing, in relation thereto, at which parties in interest, and citizens, shall have an opportunity to be heard. At least fifteen (15) days' notice of the time and place of such hearing shall be published in an official paper, or a paper of general circulation, in such municipality or county.