Calendar desk
Business Days Calculator
Count weekdays between two dates, including both endpoints.
Business Days Calculator: Count Monday-to-Friday dates within a range, including the first and last dates when they are weekdays. Saturdays and Sundays contribute nothing, while public holidays on weekdays still count. A second output gives the signed calendar-day distance, which follows a different endpoint convention from the inclusive weekday count. Runs 100% locally in your browser with zero server file uploads.
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Business days
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- Calendar-day difference
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Business days = weekdays from start through end (signed for reversed ranges)- Monday through Friday are business days; holidays are not excluded.
- Both endpoints are included. Reversed ranges return a negative count.
Formula and worked example
Business days = weekdays from start through end (signed for reversed ranges)
A worked example with sample values:
| Inputs | |
|---|---|
| Start date | Jan 6, 2025 |
| End date | Jan 10, 2025 |
| Results | |
|---|---|
| Business days | 5 |
| Calendar-day difference | 4 |
Inclusive weekday formula with a weekend
Let L be the earlier endpoint and U the later endpoint. For each date d from L through U, assign weekday indicator w(d) = 1 on Monday to Friday and 0 on Saturday or Sunday. Business days B = s × Σw(d), where s = −1 for reversed inputs and +1 otherwise. Calendar-day difference C = End date − Start date, without adding one.
For Start date 2025-01-03 and End date 2025-01-06, Friday 3 January contributes 1, Saturday and Sunday contribute 0, and Monday 6 January contributes 1. Thus B = 1 + 0 + 0 + 1 = 2 business days. C = 3 calendar days. Both outputs are correct for their respective conventions.
Range counts are not business-day offsets
The Friday-to-Monday example contains two eligible dates, but moving one business day after Friday reaches Monday. Use add business days for that offset question; it does not consume the starting date as its first day. Do not carry this range's inclusive convention into a delivery-offset calculation.
ISO's date-format overview (https://www.iso.org/iso-8601-date-and-time-format.html) explains the year-first notation used in the examples. The choice to include both weekday endpoints is this calculator's convention, not a holiday rule supplied by ISO or a guarantee that those dates are open for your workplace.
How to use it
- Enter the first date of the range; it is eligible to count.
- Enter the last date of the range; it is also eligible to count.
- Calculate the weekday count and distinguish it from the calendar-day distance.
Privacy & limitations
Dates, times and results stay in your browser. No inputs are uploaded.
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Frequently asked questions
Does a single Monday count as one business day?
Yes. If both inputs are the same Monday, the inclusive weekday count is one, while the calendar-day difference is zero. A single Saturday or Sunday contributes no business days.
Can I remove a country's holidays from the total?
This widget has no holiday selector or exclusion list. A weekday holiday remains in the count. Subtract the relevant weekday closures separately if your organisation needs an actual open-day total.
Why is the reversed range negative rather than empty?
The calculator counts eligible weekdays across the forward span, including both ends, then applies a negative sign when End date precedes Start date. The sign represents direction rather than a negative number of office openings.
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<p style="margin:4px 0 16px;font-size:13px"><a href="https://toea.com/business-days-calculator">Business Days Calculator</a> · TOEA</p>
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