Mich. Comp. Laws § 168.63

Sec. 63. The terms of office of governor and lieutenant governor shall commence at 12 noon on January 1 next following the election, and shall continue until a successor is elected and qualified. The terms of office of the governor and lieutenant governor elected at the general election of 1964 shall be 2 years. The terms of office of the governor and lieutenant governor elected at the general election in 1966 and every fourth year thereafter shall be 4 years.