Tennessee Code Title 6. Cities and Towns § 6-54-138

(a) Notwithstanding any private act of a municipality to the contrary, the legislative body of a municipality may by ordinance change the date of municipal elections to coincide with the August or November general election. The ordinance changing the election date shall provide for the extension of the terms of members of the legislative body of the municipality necessary to meet the election date, but no term may be extended for more than two (2) years beyond its regular expiration date. If an action is taken pursuant to this subsection (a), the presiding officer of the legislative body shall file a certified copy of the ordinance with the state coordinator of elections.

(b) Nothing in subsection (a) shall be construed to remove any incumbent from office or abridge the term of any incumbent prior to the end of the term for which an elected official was selected.

(c) If the legislative body of a municipality changes the date of municipal elections pursuant to subsection (a), the legislative body may at a later date change the election date back to what such date was prior to moving the election date to coincide with the August or November general election. The legislative body may only make a change under this subsection (c) one (1) time. Terms of incumbent members of the legislative body shall not be abridged to accomplish an election date change under this subsection (c); however, members elected at a date change pursuant to this subsection (c) may take office at a later date so as to not abridge terms of incumbent members of the legislative body. If such members take office at a later date, their term may be abridged due to such members having to take office at the later date.