Mich. Comp. Laws § 169.225: Campaign statement; filing; period covered.

Sec. 25.

A committee supporting or opposing a candidate or the qualification, passage, or defeat of a ballot question shall file a legibly printed or typed campaign statement. The period covered by a campaign statement is the period beginning with the day after the closing date of the most recent campaign statement filed pursuant to this act, and ending with the closing date of the campaign statement in question. If the committee filing the campaign statement has not previously filed a campaign statement, the period covered shall begin on the date on which the committee was formed.