Illinois: Night Shift & Differential Rules
Night-shift differential pay is not federally mandated under the FLSA. In Illinois, shift differentials are typically a matter of employer policy, collective bargaining agreement, or a specific industry custom. Hospitals commonly add $2 to $5 per hour for nights; manufacturing pays $1 to $3; private security pays a flat $0.50 to $1.50. Illinois wage-and-hour bulletin
Although the differential itself is voluntary, once the employer promises it, the differential becomes part of the worker's regular rate of pay for FLSA overtime calculations. That means a Illinois worker pulling overtime on a night shift should see overtime computed on base + differential, not base alone.
Use the ShiftClock night-shift differential calculator to verify your math. Common errors: forgetting to include the differential in the regular rate, paying the differential only on straight-time hours, or applying it to the wrong shift hours when a shift straddles two pay periods.
Across the ShiftClock directory, the rules in Illinois most often surface for workers on 12-hour rotations, split-shift transit and hospitality roles, and any 24/7 operation that pulls workers across the boundary between two pay periods. Match your schedule pattern in the schedules directory to see which calculators apply, then jump back here to confirm the Illinois-specific treatment. Where the rule references a dollar figure, remember that the Illinois 2025 minimum wage of $15.00 per hour anchors most premium and split-shift math.
If your employer disagrees with the calculation, document the schedule, the punches, and the pay-stub line items in writing before escalating. Illinois workers can file a wage claim with the state labor agency or the U.S. Department of Labor Wage and Hour Division when the dispute cannot be resolved internally. ShiftClock's guide directory walks through the paperwork and the typical timelines for a wage claim in plain language.