Under federal law, a workweek is any fixed, regularly recurring period of 168 hours — seven consecutive 24-hour days — that your employer designates as the cycle for tracking hours.1eCFR. 29 CFR 778.105 – Determining the Workweek It’s the only unit of time the Fair Labor Standards Act uses to decide whether you’ve crossed the 40-hour threshold for overtime, and it doesn’t have to line up with the calendar week or your pay period.
The 168-Hour Rule
The workweek is a block of 168 hours. That length never changes. It doesn’t shrink because you took a day off, and it doesn’t stretch because you pulled a double shift. Every hour you work inside that window counts toward the 40-hour overtime line, and the count resets when the next cycle begins.1eCFR. 29 CFR 778.105 – Determining the Workweek
Most people assume the cycle runs Sunday through Saturday. It can, but nothing in federal law requires it. The workweek can start on any day, at any hour — 6 a.m. Friday, midnight Wednesday, noon on Tuesday. Different groups of employees within the same company can even follow different workweeks if operations call for it. A warehouse crew might run on one cycle while the front office runs on another, and both are lawful as long as each cycle stays consistent.
Who Sets the Workweek, and Can It Change?
Your employer picks the starting point. Once it’s set, it stays fixed. Federal law does allow a change, but only if the new schedule is meant to be permanent and isn’t a maneuver to sidestep overtime. A restaurant that shifts its workweek start day every time a busy weekend pushes staff past 40 hours is breaking the rules.1eCFR. 29 CFR 778.105 – Determining the Workweek
When a legitimate change does happen, the transition creates an overlap: some hours land in both the old cycle and the new one. If the workweek previously started Monday at 7 a.m. and the employer moves the start to Sunday at 7 a.m., every hour worked that Sunday belongs to both the tail end of the old cycle and the beginning of the new one. The employer has to handle that overlap in a way that doesn’t shortchange you on overtime.2eCFR. 29 CFR 778.301 – Overlapping When Change of Workweek Is Made
Employers must keep payroll records, including the designated workweek, for at least three years.3eCFR. 29 CFR Part 516 – Records to Be Kept by Employers If you ever dispute how your hours were counted, those records are the central evidence.
The Workweek Is Not Your Pay Period
This is where a lot of confusion starts. Pay periods and workweeks are separate things. Many employers pay biweekly or semimonthly, but overtime is always calculated one workweek at a time. If a single paycheck covers two workweeks, each one is evaluated on its own.
The workweek also doesn’t have to match the calendar week. Yours might run Thursday to Wednesday even though your paystub shows Sunday through Saturday dates. The only cycle that matters for overtime is the one your employer designated.
Why the Workweek Definition Matters for Overtime
If you’re a non-exempt employee, every hour past 40 in a single workweek must be paid at one and one-half times your regular rate.4U.S. Department of Labor. Fact Sheet #23 – Overtime Pay Requirements of the FLSA Each workweek stands alone. Work 50 hours one week and 30 the next, and you’re owed 10 hours of overtime for the first week. Your employer cannot average the two weeks to arrive at 40 hours each. Averaging across workweeks is flatly prohibited.
That’s why the workweek definition carries real dollars behind it. If your employer quietly treats a biweekly pay period as a single 80-hour bucket, you can lose overtime you actually earned. The FLSA measures overtime by workweek, always.
Whether you’re eligible for overtime in the first place depends on whether you’re classified as non-exempt. Some salaried executive, administrative, and professional employees are exempt and don’t receive overtime regardless of hours worked. Job titles alone don’t decide the question; the classification turns on both a salary floor and a specific duties test.5U.S. Department of Labor. Fact Sheet #17D – Exemption for Professional Employees Under the FLSA
Sectors With a Different Kind of “Week”
The standard seven-day workweek applies to most workers, but a few industries operate under modified rules built around round-the-clock staffing. If you work in one of these fields, the 168-hour cycle isn’t necessarily your measuring stick.
Hospitals and Residential Care: the 8-and-80 System
Hospitals and residential care facilities can use a 14-day work period instead of the standard seven-day workweek. Overtime kicks in either when an employee works more than 8 hours in a single day or more than 80 hours across the full 14-day period, whichever threshold is crossed first.6eCFR. 29 CFR 778.601 – Special Overtime Provisions Available for Hospital and Residential Care Establishment Employment There’s a catch: the employer must have an agreement or understanding with the employee before the work is performed. It doesn’t have to be written, but if it isn’t, the employer must keep a special record documenting the arrangement.
The system can be genuinely useful for 12-hour nursing shifts, and it can also produce less overtime than the standard workweek method would. Run your own numbers under both systems to see which one pays you more.
Police and Firefighters: Extended Work Periods
Law enforcement and fire protection employees can work under a “work period” lasting anywhere from 7 to 28 consecutive days instead of a seven-day workweek. Within a full 28-day cycle, law enforcement officers can work up to 171 hours before overtime is required, and firefighters have a higher threshold of 212 hours.7eCFR. 29 CFR 553.230 – Maximum Hours Standards for Work Periods of 7 to 28 Consecutive Days For shorter periods, the thresholds scale proportionally. A 14-day cycle allows 86 hours for law enforcement and 106 for fire protection before overtime applies.
State Daily Overtime Rules
The FLSA only triggers overtime based on weekly hours, but a handful of states also require overtime after a certain number of hours in a single day. In those states, you can earn daily overtime even in a week where you never reach 40 total hours. State rules layer on top of the federal ones, and the standard that pays you more wins. Check your state’s labor department if you regularly work shifts longer than 8 hours.
If Your Hours Aren’t Being Counted Right
Start with your own records. A notebook, a spreadsheet, timestamped photos of your schedule — anything that documents when you actually worked. If your employer’s records go missing or conflict with what happened, your personal log becomes your best evidence.
Ask your employer, in writing, when the workweek begins. That single answer tells you how to read every paycheck. If the answer keeps changing, or if the start day seems to shift depending on how much overtime you’d otherwise be owed, that’s a red flag worth documenting.
You have two years from each underpayment to file a federal claim, extended to three years if the violation was willful.8Office of the Law Revision Counsel. 29 USC 255 – Statute of Limitations Each paycheck with missing overtime starts its own clock, so older violations may have expired while recent ones remain actionable. If you win, you can recover the unpaid overtime plus an equal amount in liquidated damages, along with reasonable attorney’s fees.9Office of the Law Revision Counsel. 29 USC 216 – Penalties
You don’t need a lawyer to start the process. The Department of Labor’s Wage and Hour Division accepts complaints online or by phone at 1-866-487-9243.10U.S. Department of Labor. Handy Reference Guide to the Fair Labor Standards Act Before you call, gather your employer’s name and address, the name of a manager or owner, a description of your work, your pay schedule, and a record of the hours in dispute. Your complaint gets routed to the nearest field office, which typically contacts you within a few business days.