Mich. Comp. Laws § 89.1: Style of ordinance; passage; required vote; effective date of ordinance.

Sec. 1.

The style of each ordinance shall be, "The city of ................... ordains." Each ordinance shall require for its passage the concurrence of a majority of all the aldermen elected or appointed, exclusive of the mayor or other officer or person legally exercising the duties of the office of mayor. The time when an ordinance takes effect shall be prescribed in the ordinance. If the ordinance imposes a sanction, the ordinance shall take effect not less than 20 days after the day of its passage.