Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.810

Sec. 810. Except when section 809  1 results in an earlier effective date, a probate court district created under section 808  2becomes effective upon the beginning date of the term for which an incumbent probate judge in any county in the district no longer seeks reelection to that office that occurs not less than 220 days after the vote on the question. At the general election immediately preceding that date, 1 probate judge for the district shall be elected as provided in section 808(5).