In addition to any other deductions allowed under this subtitle, an incarcerated individual may be allowed a deduction of 5 days from the incarcerated individual’s term of confinement for each calendar month during which the incarcerated individual manifests satisfactory performance of assigned work tasks. The deduction described in paragraph (1) of this subsection shall be calculated: from the first day that the work task is performed; and on a prorated basis for any portion of a calendar month during which the incarcerated individual performed the work task. The Commissioner shall adopt regulations governing the determination of deductions authorized under this section.