(330 ILCS 61/1-15)
    Sec. 1-15. Differential compensation.
    (a) As used in this Section, "work days" are the actual number of days the employee would have worked during the period of military leave but for the service member's military obligation. "Work days" are tabulated without regard for the number of hours in a work day. Work hours that extend into the next calendar day count as 2 work days.
    (b) Differential compensation under this Act is calculated on a daily basis and only applies to days in which the employee would have otherwise been scheduled or required to work as a public employee. Differential compensation shall be paid to all forms of active service except active service without pay. Differential compensation is calculated as follows:
        (1) To calculate differential compensation, subtract
    
the daily rate of compensation for military service from the daily rate of compensation as a public employee.
        (2) To calculate the daily rate of compensation as a
    
public employee, divide the employee's regular compensation as a public employee during the pay period by the number of work days in the pay period.
        (3) To calculate the daily rate of compensation for
    
military service, divide the employee's base pay for the applicable military service by the number of calendar days in the month the service member was paid by the military. For purposes of inactive duty, the daily rate of compensation for military service is calculated in accordance with the applicable drill pay chart issued by Defense Finance and Accounting Services.
(Source: P.A. 100-1101, eff. 1-1-19.)