Okla. Stat. tit. 57, § 57-20: Credit on fine and costs - Credit for efficient work and

good behavior.

Every county, city or town convict in this state, whether

required to work upon the public highways of the county, city or

town, in accordance with the laws of this state, or merely confined

in the county, city or town prison, shall receive credit upon his or

her fine and costs of One Dollar ($1.00) for each day confined in

prison, or worked upon the public highways, rock pile, or rock

crusher, or public work; provided that those prisoners or convicts

doing and performing the most efficient work and making the best

prisoners, shall be entitled to an additional credit of one (1) day

for every five (5) days of work, the custodian of the prison to

determine at the end of each five (5) days of imprisonment whether

or not the prisoner is entitled to such credit, and to make a record

of the decision and notify the prisoner of the same.