What counts as a business day
A business day is any day that is not a Saturday, Sunday, or public holiday. This tool counts Monday–Friday by default and optionally subtracts holidays from a chosen calendar (US Federal, UK Bank, EU Common, or your own custom list). Both endpoints are inclusive — if the start and end are the same weekday, that’s 1 business day. This inclusive counting is what trips people up on deadlines, so it’s worth confirming against your specific use case.
Three operations, one tool
| Mode | Answers |
|---|---|
| Count between dates | ”How many working days from A to B?” |
| Add business days | ”What date is 10 working days from now?” |
| Subtract business days | ”When must I start to finish by a deadline?” |
The add/subtract modes are the ones that save real time — for SLA deadlines, payment due dates, and legal notice periods, you need the calendar date that lands N working days away, skipping weekends and holidays automatically.
Where business-day math actually matters
This isn’t academic — entire business processes run on working-day counts:
- SLAs — “resolved within 5 business days” excludes the weekend the ticket sat over.
- Net terms — “Net 10 business days” payment windows.
- Settlement — markets use T+2 (trade settles 2 business days later).
- Legal notice — many jurisdictions count notice periods in working days.
Getting weekends and holidays right is the difference between hitting and missing a contractual deadline.
Holidays only count on weekdays
A subtle correctness point: the tool only deducts a holiday if it falls Monday–Friday within your range. A holiday on a Saturday is already excluded (it’s a weekend), so it doesn’t double-reduce the count. Click “view holidays included” to see exactly which dates were subtracted. For plain calendar-day spans (weekends included), use the Date Difference Calculator instead.