Mich. Comp. Laws § 113.12

Sec. 12. When, by the provisions of this act, notice of any matter or proceeding is required to be published or posted, an affidavit of the publication or posting of the same, made by the printer of the newspaper in which the same was inserted, or by some person in his employ knowing the facts, if such notice was required to be made by publication, or by the person posting the same, when required to be by posting, shall be prima facie evidence of the facts therein contained: Provided, The same shall be filed with the city clerk within 6 months from the date of the last publication thereof, or of posting the same.