(a) If a vacancy occurs in the office of Mayor or on the City Council on or before one hundred twenty (120) days before a regular election for City Council, the vacancy shall be filled at a special election for that purpose. At its next regular meeting after the occurrence of the vacancy, the City Council shall call for a special election to be held on a date that conforms with the uniform election dates set out in the Texas Election Code, as amended, if a uniform election date occurs within the one hundred and twenty (120) day period for the special election. If no such uniform election date is available, then the date for the special election shall be set within one hundred twenty (120) days from the date the vacancy occurred; and except as otherwise provided in this Charter such special election laws as set out in the Texas Election Code, as amended, shall be applicable to, and control in all such elections.
(b) A person elected either at a special election or a regular election to fill a vacancy in the office of Mayor or on the City Council shall serve only the unexpired term of the Mayor or City Council member whose place has been declared vacant, as the case may be.
(c) If a candidate duly elected either to the office of Mayor or to the City Council at the general election fails to take the oath of office on or before ten (10) days after the official canvass of the election, then his place shall be considered a vacancy and filled as herein provided for other vacancies. In the event such a candidate, elected either to the office of Mayor or to the City Council at a special election, fails to take the oath of office on or before ten (10) days after the official canvass of the election, then his place shall be considered a vacancy and filled as herein provided for other vacancies.