Michigan Compiled Laws, Chapter 801. Jails and Workhouses § 801.214

Sec. 14. The superintendent of said work farm, factory or shop shall cause to be kept a record of each and all infractions of the rules and discipline of such work farm, factory or shop with the names of the person or persons offending, and the date and character of such offense; and every person therein detained whose name does not appear upon such record shall be entitled to a deduction of 3 days per month from his sentence for each month he shall continue to obey all the rules of the said work farm, factory or shop.