Overtime Is Weekly, Not Per Paycheck: The Timesheet Rule Payroll Gets Wrong

Written by Rachel Kim, Payroll Operations Editor

Fact-checked against DOL regulations & payroll standards & primary sources · Last updated July 2026

Here is a payroll error so common it feels correct: an employee works 45 hours one week and 35 the next, the biweekly timesheet totals 80, and the system pays no overtime. That is a straightforward FLSA violation — and it happens because pay periods and workweeks are different objects that merely resemble each other.

Key Takeaways

Federal overtime is computed per fixed, recurring 168-hour workweek — never per pay period.
45 + 35 across two weeks = 5 overtime hours owed, even though the biweekly total is exactly 80.
Averaging hours across weeks is prohibited for non-exempt employees, whatever the pay frequency.
“Comp time” instead of overtime pay is generally illegal in the private sector.

Why Averaging Fails

The workweek is the FLSA’s atomic unit: seven consecutive 24-hour periods, fixed in advance by the employer. Each week closes its own books. Hour 41 of week one is an overtime hour at the moment it is worked; nothing in week two can retroactively un-work it. Semimonthly pay periods make this worse — they slice mid-week, so a period’s timesheet total is not even a whole number of workweeks.

Our Framework: The Workweek Lock. Audit any timesheet in three moves. (1) Mark the employer’s workweek boundary on the raw punches — not the pay period boundary. (2) Total each workweek separately. (3) Pay each week’s excess over 40 at 1.5× that week’s regular rate. Example at $18/hour: week one 45 hrs → $720 + 5 × $27 = $855; week two 35 hrs → $630. Correct total $1,485. The “80 hours, no OT” shortcut pays $1,440 — $45 short per occurrence, times every employee with an uneven fortnight, times a 2–3 year federal look-back.

The Regular-Rate Trap Inside the Overtime Line

Overtime is 1.5 × the regular rate, which is not always the base wage: nondiscretionary bonuses, shift differentials, and most commissions must be folded into the rate before multiplying. A $50 weekly attendance bonus on 45 hours raises the regular rate by $1.11 and the five OT hours by about $8.33 — small per week, systematic per year.

Frequently Asked Questions

Can our workweek start on a Wednesday?

Yes — any fixed day and hour works, and different groups can have different workweeks, as long as they do not shift to dodge overtime.

Is unapproved overtime still owed?

Yes. Working time the employer suffers or permits must be paid; the remedy for policy violations is discipline, never non-payment.

Can employees bank hours as comp time instead?

Public-sector employers may under strict rules; private employers generally may not substitute comp time for FLSA overtime pay.

This article is educational and reflects federal FLSA rules and standard payroll conventions as of 2026, verified against Department of Labor regulations and guidance. State rules can differ. It is not legal or accounting advice.

The Split Week on a Semimonthly Timesheet

The regulation behind all of this is short enough to memorize: 29 CFR 778.104 says each workweek stands alone. The practical headache it creates for semimonthly payroll is the split week — a workweek that starts in one pay period and ends in the next, so on the 15th nobody yet knows whether Tuesday’s hours were regular or overtime.

The accepted mechanics: pay the split week’s hours at straight time in the period when they were worked, then settle the overtime premium in the paycheck for the period in which the workweek closes, once the weekly total exists. Take a $20/hour employee whose workweek lands at 42.5 hours across the boundary. The week’s correct value is 40 × $20 + 2.5 × $30 = $800 + $75 = $875; whatever straight-time portion the first check already carried, the second check must bring the week’s cumulative pay to that figure. A timesheet system that cannot report per-workweek totals across pay-period lines cannot do this reconciliation — which is the real test to run before buying one.

Changing the Workweek Without Creating a Violation

Employers sometimes want to move the boundary — say from Sunday-start to Wednesday-start to match scheduling. That is allowed, but only as a permanent change made for legitimate business reasons, not a maneuver timed to bury a heavy week. During the transition, the DOL’s method requires computing pay under both the old and new workweek definitions for the overlap days and paying whichever result is greater. Document the effective date, announce it in advance, and keep the memo; a workweek that shifts quietly in the timesheet software, with no paper behind it, looks exactly like evasion in an audit even when it was innocent.

Does a mid-week holiday change the overtime threshold?

No. Only hours actually worked count toward the 40; eight hours of holiday pay on Monday do not make Saturday’s ninth worked hour overtime under federal law, though some employers voluntarily count it.

Do two jobs at the same employer share one workweek total?

Yes — hours for the same employer combine, and overtime is owed on the blended (weighted-average) regular rate across both roles.

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