Article — Working Days Calculator
Working days: counting weekdays between dates the way payroll does
A working day in the United States is any Monday through Friday that is not a federal holiday. The standard year contains 365 calendar days, 261 weekdays, and 11 federal holidays, which leaves roughly 250 working days. That figure is the basis for payroll cycles, project timelines, shipping ETAs, contract turnaround windows, and almost every "business day" clause in US commercial agreements. The calculator above counts working days between any two dates with optional federal-holiday exclusion, returning the result alongside calendar days, weekend days, and the holiday count.
The math is direct — calendar days minus weekend days minus holidays — but the inputs require care. Different agencies and contracts mean slightly different things when they say "working days," and the difference between including or excluding the start date can change a five-day project into a six-day one.
What working days means
The phrase "working day" refers to a day on which standard commercial business takes place. In the United States and most western countries, that means Monday through Friday, eight hours a day, excluding public holidays. The opposite of a working day is either a weekend day or a holiday. The two are kept distinct because employees are typically not paid for weekends but are paid for holidays — even though both reduce the count of days available for work.
The US Office of Personnel Management defines the federal working week as 40 hours, Monday through Friday. The 11 recognized federal holidays drop that to roughly 250 days. Other definitions vary: the ACA counts employment in 30-hour weeks, the BLS uses 35 hours for full-time threshold.
The phrase "business day" appears in federal regulations roughly 4,000 times — in everything from securities settlement (T+1 since 2024) to consumer-protection notices to truck-driver rest periods. The Securities and Exchange Commission, the Federal Trade Commission, and the Department of Labor each have slightly different official definitions, mostly because the holidays they observe are not identical. The SEC follows the New York Stock Exchange calendar, which adds Good Friday but not Columbus Day or Veterans Day — so a "business day" in the securities world is not the same as a "business day" for federal employees.
The working-days formula
Working days equals calendar days minus weekend days minus holidays. The three categories are mutually exclusive — a holiday on a Sunday counts as a weekend day, not a holiday, because the day was already not a working day.
WD = CD - W - H working days = cal - weekends - holidaysWD ≈ (5/7) × CD - H quick approximation30 calendar days ≈ 22 working days1 year ≈ 250 working daysFor mental math, the "times five over seven" rule gives a good estimate. A 30-day window has about 21-22 working days before holidays. A 90-day window has about 64-65. A full year has about 261 weekdays, dropping to 250 after the 11 federal holidays. The exact count varies by start day and by which year you pick.
Working days per year in the US
The US working year hovers around 250 days. The exact number depends on which day of the week January 1 falls on and how many of the 11 federal holidays end up on weekends. When a holiday falls on Saturday or Sunday, OPM observes it on the adjacent weekday — so the "working day lost" happens on a Friday or Monday instead.
- 2024 252 working days (1 federal holiday on weekend)
- 2025 251 working days
- 2026 251 working days
- 2027 251 working days (Christmas falls on Sat, observed Fri)
- Total weekdays in non-leap year 261
- Federal holidays 11 (since Juneteenth added 2021)
- Working hours per year ~2,000 at 8 hours/day
- Working weeks per year ~50
US federal holidays and observance
The federal government recognizes 11 holidays under 5 USC 6103. Five are fixed-date and the rest are floating Monday holidays under the Uniform Monday Holiday Act of 1968. Each is a non-working day for federal employees; private-sector observance follows employer policy.
The OPM observance rule shifts holidays that fall on weekends. When New Year's Day falls on Saturday, the federal holiday is observed on the prior Friday. The calculator handles these shifts automatically.
Working-day uses in business
Working days appear in contracts to specify deadlines that are immune to weekends. A "30 working days" turnaround is six weeks of calendar time. Shipping carriers express transit times in business days because Saturdays and Sundays are not normal pickup or delivery days.
When negotiating contracts, always specify whether "days" means working days, business days, or calendar days. The Securities Industry and Financial Markets Association uses "trade days" (working days on which the relevant exchange is open). Federal Reserve regulations use "business days" (working days for banks). Courts use "court days" in some jurisdictions. The default in plain English is calendar days, which means weekends count.
Payroll is the largest working-day application. Most US workers are paid biweekly (26 paychecks per year) on a fixed weekday, typically Friday. Pay periods with holidays shift payment to the next working day.
Working days around the world
The five-day Monday-Friday week is the global standard for the OECD, but exceptions exist. Israel runs Sunday-Thursday, observing the Jewish Sabbath on Saturday. Saudi Arabia and the UAE have shifted toward Sunday-Thursday or Monday-Friday over the past decade for alignment with global commerce. Iran runs Saturday-Wednesday.
National holiday counts also vary. The UK has 8 bank holidays. Germany has 9-13 depending on state. Japan has 16 public holidays, the highest among major economies. Mexico has only 7 statutory holidays.
If a contract spans multiple jurisdictions, "working days" needs a defined holiday calendar. The default assumption — "the working days of the relevant party's home jurisdiction" — produces enforcement gaps when one party's home country is in holiday and the other expects deadline performance. Specify a single holiday calendar or use a neutral standard like "TARGET2 settlement days" for euro-area transactions.
The 100-year history of the five-day workweek
Henry Ford instituted a five-day workweek at Ford Motor Company in 1926, partly as a productivity experiment and partly to encourage consumption — workers with two days off bought more cars. The Fair Labor Standards Act of 1938 established the 40-hour week as the trigger for overtime pay but did not mandate a five-day schedule.
The most recent push has been toward a four-day workweek, with pilots in the UK, Iceland, and Belgium showing productivity holds steady when hours drop from 40 to 32 with no pay reduction. The five-day standard remains dominant in the US but is increasingly contested.
Common working-day mistakes
Forgetting to include or exclude the start date. A 5-working-day deadline starting Monday could mean "due by end of Friday" (Mon-Fri inclusive) or "due Monday of next week" (5 days after Monday). Contract language usually clarifies; default convention is the next 5 working days inclusive.
Treating "business day" and "working day" as identical when they are not. Some industries use one term to mean "day the relevant institution is open" (which excludes the institution's specific holidays) and the other to mean any Monday-Friday. Read the definitions section of any contract.
Forgetting the OPM weekend-observance rule. When a holiday falls on Saturday or Sunday, the federal observance shifts to a weekday — adding a non-working day where you would not expect one. Use a calculator with observed dates rather than statutory dates.
Mixing up working days with paid hours. The BLS standard year of 2,080 paid hours counts holidays as paid time. The working-day count of 250 days × 8 hours = 2,000 hours does not. The difference is small but matters for accrual calculations.
Counting Friday-after-Thanksgiving as a federal holiday. It is not. Many private employers grant it as a paid day off, but OPM does not list it among the 11 federal holidays. If your calculator excludes it, the source is non-federal.