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Formula
Business days = Calendar days − Weekend days − Federal holidays observed on weekdays
- Calendar days
- every day from the start date up to the end date (the end date is counted only when "Include the end date" is ticked)
- Weekend days
- Saturdays and Sundays in the range
- Federal holidays
- the 11 US federal holidays, on the weekday they are observed (Saturday → Friday before, Sunday → Monday after)
Two ways to use the business days calculator
Count business days answers “how many working days are there between these dates?” Enter a start and end date. The result is the number of business days, with the calendar days, weekdays, weekend days and the federal holidays that were removed. Any holidays in the range are listed with the date they are observed.
Add business days answers “what date is N working days from now?” Enter a start date, choose forward or back, and the number of business days. The result is the target date, with the weekend days and holidays that were skipped on the way. Use it for shipping estimates, response deadlines, notice periods and payment terms such as “net 10 business days”.
Both modes let you untick Exclude US federal holidays to count plain Monday-to-Friday weekdays.
How to calculate business days between two dates
Take Monday, November 2 to Friday, November 27, 2026, counting both dates.
- Calendar days: November 2 to 27 inclusive is 26 days.
- Weekend days: three full weekends fall in that span (Nov 7–8, 14–15 and 21–22), so 6 weekend days, leaving 20 weekdays.
- Holidays: Veterans Day (Wednesday, November 11) and Thanksgiving (Thursday, November 26) are both weekdays.
- Business days: 26 − 6 − 2 = 18.
Adding works the other way round. Five business days after Wednesday, December 23, 2026: December 24 is day 1, Christmas Day (Friday) is skipped, the weekend is skipped, and December 28, 29, 30 and 31 are days 2 to 5. The answer is Thursday, December 31, 2026.
US federal holidays the calculator excludes
Federal holidays are set by 5 U.S.C. 6103. Five have fixed dates and six fall on a set weekday, so the calculator works them out for any year rather than relying on a list. Observed dates published by OPM:
| Holiday | Rule | Observed 2026 | Observed 2027 |
|---|---|---|---|
| New Year’s Day | January 1 | Thu, Jan 1 | Fri, Jan 1 |
| Martin Luther King Jr. Day | 3rd Monday in January | Mon, Jan 19 | Mon, Jan 18 |
| Washington’s Birthday | 3rd Monday in February | Mon, Feb 16 | Mon, Feb 15 |
| Memorial Day | Last Monday in May | Mon, May 25 | Mon, May 31 |
| Juneteenth | June 19 | Fri, Jun 19 | Fri, Jun 18 |
| Independence Day | July 4 | Fri, Jul 3 | Mon, Jul 5 |
| Labor Day | 1st Monday in September | Mon, Sep 7 | Mon, Sep 6 |
| Columbus Day | 2nd Monday in October | Mon, Oct 12 | Mon, Oct 11 |
| Veterans Day | November 11 | Wed, Nov 11 | Thu, Nov 11 |
| Thanksgiving Day | 4th Thursday in November | Thu, Nov 26 | Thu, Nov 25 |
| Christmas Day | December 25 | Fri, Dec 25 | Fri, Dec 24 |
The observed-date rule is why July 4, 2026 (a Saturday) is observed on Friday, July 3, and why Christmas 2027 (also a Saturday) is observed on Friday, December 24.
Business days in each month of 2027
Calculated with the business days calculator, counting every date in the month:
| Month | Weekdays | Business days (federal holidays excluded) |
|---|---|---|
| January | 21 | 19 |
| February | 20 | 19 |
| March | 23 | 23 |
| April | 22 | 22 |
| May | 21 | 20 |
| June | 22 | 21 |
| July | 22 | 21 |
| August | 22 | 22 |
| September | 22 | 21 |
| October | 21 | 20 |
| November | 22 | 20 |
| December | 23 | 21 |
| Year | 261 | 249 |
December 2027 loses two days: Christmas (observed December 24) and New Year’s Day 2028, which falls on a Saturday and is observed on Friday, December 31, 2027. That is why 2027 has 12 observed federal holidays and 2028 only 10.
Where business day counts matter
- Shipping and delivery. “Arrives in 5–7 business days” excludes weekends and usually holidays.
- Contracts and notices. Response windows, cure periods and cancellation rights are often written in business days.
- Payroll and invoices. Payment terms and direct-deposit timing depend on bank business days.
- Project planning. Converting a duration in working days into a calendar end date.
For plain calendar-day differences, use the date difference calculator; to add calendar days, weeks or months, use the date calculator.
Common mistakes
- Counting the start date when adding. “Within 3 business days of Monday” normally means by Thursday, not Wednesday.
- Forgetting observed holidays. A holiday on a Saturday still removes the Friday for federal offices.
- Assuming every employer follows the federal calendar. Many private employers close for fewer holidays, and some add the day after Thanksgiving or Christmas Eve.
- Mixing up bank days and federal workdays. Banks follow the Federal Reserve schedule, which keeps Fridays before Saturday holidays open.
Worked examples
Working days in a quarter
January 1 to March 31, 2027, counting both dates and excluding New Year’s Day, Martin Luther King Jr. Day and Presidents Day.
Inputs (Count business days): Start date = 2027-01-01; End date = 2027-03-31; Include the end date = Yes; Exclude US federal holidays = Yes
90 calendar days − 26 weekend days − 3 federal holidays = 61 business days
Answer: 61 business days from Friday, January 1, 2027 to Wednesday, March 31, 2027 (end date included), excluding US federal holidays.
10 business days after a Thanksgiving-week order
A delivery promised 10 business days after Monday, November 23, 2026, skipping Thanksgiving.
Inputs (Add business days): Start date = 2026-11-23; Direction = Add (forward); Business days = 10; Exclude US federal holidays = Yes
Start the count the day after Monday, November 23, 2026; count Monday–Friday only, skipping observed federal holidays. 10 business + 4 weekend + 1 holiday = 15 calendar days
Answer: 10 business days after Monday, November 23, 2026 is Tuesday, December 8, 2026 (US federal holidays skipped).
A holiday that falls on a Saturday
June 14 to 25, 2027. Juneteenth is Saturday, June 19, so it is observed on Friday, June 18.
Inputs (Count business days): Start date = 2027-06-14; End date = 2027-06-25; Include the end date = Yes; Exclude US federal holidays = Yes
12 calendar days − 2 weekend days − 1 federal holidays = 9 business days
Answer: 9 business days from Monday, June 14, 2027 to Friday, June 25, 2027 (end date included), excluding US federal holidays.
Counting back 15 business days
A deadline 15 business days before Friday, January 8, 2027, across Christmas and New Year’s Day.
Inputs (Add business days): Start date = 2027-01-08; Direction = Subtract (back); Business days = 15; Exclude US federal holidays = Yes
Start the count the day before Friday, January 8, 2027; count Monday–Friday only, skipping observed federal holidays. 15 business + 6 weekend + 2 holiday = 23 calendar days
Answer: 15 business days before Friday, January 8, 2027 is Wednesday, December 16, 2026 (US federal holidays skipped).
Assumptions and limitations
- Business days are Monday to Friday. In Count mode the start date is always counted; the end date is counted only if you tick "Include the end date". Reversed dates are swapped.
- In Add mode the start date is not counted. Counting begins with the next business day (or the previous one when subtracting), so a weekend or holiday start counts from the next working day.
- Holidays follow the federal rules in 5 U.S.C. 6103 and the OPM observance rule for most federal employees, a Saturday holiday on the preceding Friday and a Sunday holiday on the following Monday. They are computed by rule for every year, so no table needs updating.
- Juneteenth is included from 2021 and Martin Luther King Jr. Day from 1986. Holiday counting starts in 1986; for earlier dates, untick the holiday option to count weekdays only.
- Inauguration Day, state and local holidays, company closures and religious holidays are not excluded. Banks and the Federal Reserve stay open on the Friday before a Saturday holiday, so their business days can differ by a day.
Frequently asked questions
How do you calculate business days between two dates?
Count the calendar days, subtract the Saturdays and Sundays, then subtract any holidays that fall on a weekday. Monday, November 2 to Friday, November 27, 2026, inclusive, has 26 calendar days and 20 weekdays; Veterans Day and Thanksgiving fall on weekdays, so there are 18 business days.
How long is 7–10 business days?
With no holidays in the way, 7 business days from a Monday lands on the Wednesday of the following week (9 calendar days), and 10 business days lands on the Monday two weeks later (14 calendar days). A federal holiday in between adds a day to each.
How long is 3 business days?
Three working days after the start date. From a Monday, that is Thursday; from a Wednesday it is the following Monday, because Saturday and Sunday are skipped. If a holiday falls in between, add one more day.
Does the calculator include the start and end dates?
In Count mode the start date is included and you choose whether to include the end date; it is ticked by default, so Monday to Friday of the same week counts as 5 business days. In Add mode the start date is never counted, which matches how most deadlines are worded.
How many business days are in a year?
There are 260 or 261 weekdays in a year. Taking out federal holidays leaves about 249 to 251. For example, 2026 has 250 and 2027 has 249, because New Year's Day 2028 falls on a Saturday and is observed on Friday, December 31, 2027.
What happens when a holiday falls on a weekend?
For most federal employees, a Saturday holiday is observed on the Friday before and a Sunday holiday on the Monday after. The calculator moves holidays the same way, so Independence Day 2027, a Sunday, removes Monday, July 5 from the count.
Are banks closed on the same days?
Mostly, but not always. The Federal Reserve Banks are closed on Sunday-holiday Mondays but open on the Friday before a Saturday holiday. For bank deadlines, check whether that Friday should count as a business day.
Sources
- Federal Holidays — U.S. Office of Personnel Management. Checked October 10, 2026.
- 5 U.S. Code § 6103 – Holidays — Legal Information Institute, Cornell Law School. Checked October 10, 2026.
- Holidays Observed – K.8 — Board of Governors of the Federal Reserve System. Checked October 10, 2026.