The first primary election under the provisions of this charter shall be held on Tuesday, July 14, 1970; and the first such general Municipal election shall be held on Tuesday, July 28, 1970, to elect officers, whose terms shall begin on August 17, 1970, and expire as soon after December 31, 1973, as their successors are elected and qualified. The appropriate certificates of candidacy for such first primary election shall be filed on or before July 6, 1970.