Business Days Calculator
Count Monday-to-Friday days between two dates, inclusive, with a worked September 2026 example and how to subtract public holidays by hand.
Results
Business days (inclusive)
You might also need
Educational estimates · not financial advice · free, no signup
Formula / how it works
Business days = number of dates from start to end, inclusive, that fall on Monday through Friday. Public holidays are not removed; subtract them yourself.
Read the guide: Date and Time Calculations: Leap Years, Business Days and Time Zones
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
A business day is a weekday, Monday to Friday. This calculator counts every such day between a start and end date, counting both end dates when they are weekdays. It is useful for delivery estimates, invoice terms, notice periods, project plans and contract deadlines that are written in business days rather than calendar days. The tool excludes Saturdays and Sundays only. Public and bank holidays differ by country and region and change from year to year, so they are not built in. Count the holidays that fall in your range separately and subtract them from the result. If your working week is not Monday to Friday, the count will not match your schedule.
When to use / who it helps
- A contract says payment is due within a number of business days.
- You are estimating how many working days a project phase has.
- You need the number of working days in a month for pay or capacity planning.
- You are checking a shipping or processing time quoted in business days.
- You want to compare calendar days with working days for a deadline.
How to use
Steps
- Enter the start date.
- Enter the end date.
- Read the inclusive count of weekdays.
- Identify public holidays that fall on weekdays within the range.
- Subtract each of those holidays from the count.
- To find a due date after N business days, use a workday-offset tool rather than this count.
How to interpret results
- The result includes both the start and the end date when they are weekdays.
- A full calendar week always contains five business days.
- Calendar days minus business days equals the weekend days in the range.
- Months with five weekends have fewer business days.
- The count does not reflect company shutdowns or local holidays.
Common mistakes & gotchas
- Forgetting to subtract public holidays.
- Treating the count as exclusive of the start date when the tool is inclusive.
- Using it for a six-day working week.
- Assuming "within five business days" starts counting on the same day as the event.
- Entering the dates in the wrong order.
Worked example
Worked example — 1 to 30 September 2026
- September 2026 has 30 days, and 1 September is a Tuesday.
- Weekend days in the range: 5, 6, 12, 13, 19, 20, 26 and 27 September, a total of 8.
- Business days: 30 − 8 = 22.
- In the United States, Labor Day falls on Monday 7 September 2026, so a US working-day count would be 22 − 1 = 21.
Result: There are 22 weekdays between 1 and 30 September 2026, or 21 after removing a single US holiday.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
Business days = number of dates from start to end, inclusive, that fall on Monday through Friday. Public holidays are not removed; subtract them yourself.
Frequently asked questions
Does the count include the start and end dates?
Yes, both are counted when they fall on weekdays.
Are public holidays excluded?
No. Subtract any holidays in the range yourself.
How many business days are in a typical year?
Roughly 260 weekdays, before holidays.
What counts as a business day?
Usually Monday to Friday, but contracts and countries may define it differently.
How do I find the date after a number of business days?
Add weeks first (five business days per week) and then the remainder, skipping weekends and holidays.
Why might my result differ from a bank's?
Banks follow their own holiday calendars and cut-off times.