Mich. Comp. Laws § 15.93: Official oaths and certificates or bonds; time for filing.

Sec. 3.

Every such officer, except where otherwise directed by law, shall file his oath of office and certificate or bond aforesaid, as the case may be, within 60 days from the receiving of his commission or appointment; and in default thereof, such commission or appointment shall be null and void: Provided, That officers appointed in and for the counties of Mackinac, Chippewa, Schoolcraft, Houghton, Ontonagon and Marquette, shall file their oaths, certificates and bonds as herein provided, within 90 days from their appointment or commission.