Mississippi Code Title 37. Education § 37-7-227

(1) The county election commissioners shall indicate on the ballot which of the persons whose names appear thereon are candidates for a full term, and which of such persons, if any, are candidates for an unexpired term or terms. The candidate who receives a majority of the votes cast, either for a full term or for an unexpired term or terms, as indicated on the ballot, shall be declared elected, and the person or persons elected to a full term shall assume the duties of his office on the first day of January of the year following such election. The person or persons elected to an unexpired term(s) shall assume office immediately. If no candidate receives a majority of the votes cast at the election, a runoff shall be held in the same manner four (4) weeks after the election between the two (2) candidates receiving the highest number of votes upon the first ballot.

(2) Notwithstanding any other provision of law, if an election for school board trustees occurs on a Tuesday, during a general election, any runoff for such election shall occur four (4) weeks after the election.