It feels fair. Eighty hours across two weeks is eighty hours of work, and the employee got a short week to balance a long one. The Fair Labor Standards Act does not see it that way, and the gap between the two readings is money the employer already owes.

The Rule, and What a Workweek Is

Under federal law, overtime is computed against a single fixed workweek: a recurring period of 168 consecutive hours that the employer defines in advance. It can start on any day and at any hour, but once set it stays set. Every workweek stands alone. Hours cannot be averaged across two or more weeks, whatever the pay schedule says.

A biweekly pay period is an accounting convenience. It is not a unit of overtime law.

So 45 and 35 is not eighty hours with no overtime. It is one workweek carrying five overtime hours and one workweek carrying none, and the paycheck has to reflect both.

What the Mistake Costs

Put a rate on it. At $20 an hour, here is the same pair of weeks read both ways.

One employee, two weeks, $20 an hour. The only difference between the two columns is whether the hours were averaged.
Pay componentAveraged across the periodComputed per workweek
Week 1, 45 hourscounted into an 80-hour total40 regular plus 5 at time and a half
Week 2, 35 hourscounted into an 80-hour total35 regular
Overtime hours recognized05
Gross pay for the period$1,600.00$1,650.00
$1,300 a year

The shortfall for one employee at $20 an hour if that 45-and-35 pattern repeats every pay period: $50 short per period across 26 periods. Back pay is the smallest part of the exposure, since the FLSA also provides for liquidated damages equal to the unpaid wages, and a two-year lookback that becomes three years for a willful violation.

Why the Mistake Is So Common

Because the arithmetic invites it. Most downloadable biweekly timesheets present fourteen day-rows and one grand total, and a single total is precisely the number the law does not care about. The error is not malicious, it is structural: the paper computes the wrong quantity, and everything downstream trusts the paper. Our biweekly timesheet generator subtotals each workweek separately and splits overtime inside each one before totaling the period, which is the whole reason it exists as a separate document from the weekly sheet.

The Comp-Time Cousin

The same instinct produces a second violation: take Friday off next week instead of overtime this week. For private-sector employees who are not exempt, compensatory time in place of overtime pay is generally unlawful. The statute permits it for public agencies under specific conditions and does not extend that permission to private employers. Banking hours from a long week against a short one is averaging wearing a friendlier name.

What Correct Looks Like

Each workweek subtotaled on its own. Hours over 40 in either week paid at one and a half times the regular rate for that week. The two weeks then summed for the paycheck. Some states add stricter layers on top, and California adds four more triggers, but the federal per-week floor applies everywhere in the country.

There is a one-line audit any owner can run today: look at your timesheet and find the per-week subtotal. If it is not there, the sheet cannot be showing correct overtime, because it is not computing the quantity the law measures.