(1) Whenever any able-bodied prisoner is confined in the county jail or the jail of any town or city, having been convicted of a misdemeanor or of a violation of an ordinance of such town or city, the sheriff of such county, or the marshal or the chief of police of such town or city, under the direction of the county commissioners or the governing body of the town or city, may allow such persons to work at suitable public or charitable employment for not more than eight hours on each working day.

(2) A person so employed shall receive a credit on any fine and costs imposed in an amount equal to $5 for each full hour spent by the person in the specified work.

(3) Persons held in jail and awaiting trial or held on civil process, may, with their consent, be likewise so employed and shall receive a credit on any fines and costs in an amount equal to $5 for each full hour spent by the person in the specified work, or if there are no such fines and costs, compensation for such employment in an amount agreed to by the person and the city or county, but not less than $5 a day, to be paid by the city or the county.

(4) Any prisoner employed as above provided, shall continue to be deemed prisoners during the hours of their employment and subject to all laws, rules and regulations relating to prisoners.