Mich. Comp. Laws § 168.644e

Sec. 644e. Except as provided in section 642, an officer required to be elected at the odd year general election must be nominated at the odd year primary election. If a charter provides for nomination by caucus or by filing a petition or affidavit directly for the general election, the candidate filing deadline or certification deadline is 4 p.m. on the fifteenth Tuesday before the odd year general election. If a charter provides for the election at the primary of a candidate who receives more than 50% of the votes cast for that office, the candidate filing deadline or certification deadline is 4 p.m. on the fifteenth Tuesday before the primary.