Mich. Comp. Laws § 211.37
The county board of commissioners, either at a session held not later than October 31 in each year or at a special meeting held for a local tax collecting unit that approves under section 44a(2) the accelerated collection in a summer property tax levy of a millage that had been previously billed and collected as in a preceding tax year as part of the winter property tax levy, shall ascertain and determine the amount of money to be raised for county purposes, and shall apportion the amount and also the amount of the state tax and indebtedness of the county to the state among the several townships in the county in proportion to the valuation of the taxable real and personal property as determined by the board, or as determined by the state tax commission upon appeal in the manner provided by law for that year, which determination and apportionment shall be entered at large on county records. The board, at a session held not later than October 31 in each year, shall also examine all certificates, statements, papers, and records submitted to it, showing the money to be raised in the several townships for school, highway, drain, township, and other purposes. It shall hear and consider all objections made to raising that money by any taxpayer affected. If it appears to the board that any certificate, statement, paper, or record is not properly certified or is in any way defective, or that any proceeding to authorize the raising of the money has not been had or is in any way imperfect, the board shall verify the same, and if the certificate, statement, paper, record, or proceeding can then be corrected, supplied, or had, the board shall authorize and require the defects or omissions of proceedings to be corrected, supplied, or had. The board may refer any or all the certificates, statements, papers, records, and proceedings to the prosecuting attorney, who shall investigate and without delay report in writing his or her opinion to the board. The board shall direct that the money proposed to be raised for township, school, highway, drain, and all other purposes authorized by law shall be spread upon the assessment roll of the proper townships, wards, and cities. This action and direction shall be entered in full upon the records of the proceedings of the board and shall be final as to the levy and assessment of all the taxes, except if there is a change made in the equalization of any county by the state tax commission upon appeal in the manner provided by law. The direction for spread of taxes shall be expressed in terms of millages to be spread against the taxable values of properties and shall not direct the raising of any specific amount of money. This section does not apply when section 36(2) applies and shall not prevent the township clerk from providing a certification to the county clerk pursuant to section 36(1). If a certification is provided pursuant to section 36(1), the county board of commissioners shall meet and direct or amend its direction for the spread of millages by local units in the county pursuant to the certification.
MCL 211.37