(a) A regular city election shall be held in the several voting precincts of the city at such place therein as shall be designated by the council on the 3rd Monday in May 1966 and every fourth year thereafter.
(b) A non-partisan city primary election shall be held on the 1st Monday in April, 1966, and every four years thereafter, if nominating petitions for candidates eligible to be placed on the ballot to a number greater than twice the number of positions to be filled in any elective office shall have been filed with the clerk as provided in this charter.