The mayor, or in the mayor's absence the vice mayor, shall take the chair at the hour appointed for the formal meeting and shall call the council to order. In the absence of the mayor and the vice mayor, the city clerk shall call the council to order, whereupon an acting mayor shall be elected by the council members present. Upon the arrival of the mayor or vice mayor, the acting mayor shall relinquish the chair at the conclusion of the business then before the council. (1962 Code § 2-3.06)