Business Days Calculator
Find the business days between two dates, or add working days to a start date, using your own weekend pattern and holiday list.
Formula & worked example
Formula: Business days = calendar days − weekend days − holidays that fall on working days.
Example: 1–7 January 2024 with Saturday/Sunday off and 3 January a holiday: 7 − 2 − 1 = 4 business days.
Method & source: ISO 8601 weekday numbering; weekends and holidays are user-defined. See how we test our calculators.
Next step: try total days between two dates or work hours with breaks.
What Is a Business Days Calculator?
A business days calculator counts only the working days between two dates. It skips weekends and any public holidays you list, so you get the number of days that people can genuinely work, ship or respond.
Unlike a simple calendar count, this tool lets you define the weekend yourself. That matters when your team works Sunday to Thursday, runs a six-day week or observes company-specific closures.
How Our Business Days Calculator Works
Choose a mode: count business days between two dates, or add a number of business days to a start date to find a deadline.
- Custom weekends: Tick the days of the week that are non-working for you.
- Excluded holidays: Add individual dates and they are removed from the count only if they fall on a working day.
- Include or exclude the end date: Match the way your contract or SLA counts days.
- Full breakdown: Business days, weekend days, holidays skipped and total calendar days.
- Deadline mode: Add or subtract working days from any date and see the resulting weekday.
A holiday that lands on a weekend is not counted twice, so the totals always add up to the calendar span.
Why Counting Business Days Matters
Deadlines, delivery promises and payment terms are almost always written in business days, yet calendars only show calendar days.
- Estimate shipping and delivery windows realistically.
- Work out invoice due dates and payment terms such as “net 10 business days”.
- Plan project timelines and notice periods without over-promising.
- Calculate leave, processing times and statutory response periods.
- Support teams that work non-standard weeks in the Middle East, Asia or shift-based industries.
Using the business days between two dates instead of calendar days keeps your commitments accurate and your customers informed.
Worked walkthrough: a delivery promise
A supplier promises delivery within 10 business days of an order placed on Monday 6 July 2026. With Saturday and Sunday as the weekend and no holidays, ten working days after that Monday lands on Monday 20 July 2026. If 9 July is a public holiday and you add it to the holiday list, the calculator skips it and the date moves to Tuesday 21 July. Switching to “between two dates” mode with 6 July and 20 July confirms the same 10 business days, and shows the 14 calendar days and 4 weekend days involved.
Practical tips for business days calculations
- Decide first whether the start day counts. Many contracts count from the day after an event, so start the calculation on the next business day if that is your rule.
- For a Sunday-to-Thursday working week, tick Friday and Saturday as the weekend instead of the default Saturday and Sunday.
- Add local and regional holidays too, not only national ones – a single missed holiday can move a deadline by a full day.
- Use the negative option in “Add business days” to work backwards, for example to find the last date to place an order for an event.
- Half days and company shutdowns can be added as holidays, but partial days are not counted – treat them as full days off or full working days.
Frequently Asked Questions (FAQs)
Enter a start and end date, keep Saturday and Sunday ticked as weekend days (or change them), add any holidays and press Calculate. The result shows the working days in that range.
Yes. Tick any combination of weekdays as non-working. For example choose Friday and Saturday for a Middle Eastern week, or only Sunday for a six-day working week.
Pick a date and add it to the holiday list. Each listed date that falls on a working day reduces the business-day total by one. You can remove a date at any time.
The start date is always counted if it is a working day. Use the “Include end date” option to decide whether the end date is counted too.
Yes. Switch to “Add business days”, enter a start date and a number of working days, and the calculator gives you the resulting date. Use a negative number to count backwards.
Confirm official deadlines. Results follow the calendar rules described on this page. Contracts, court time limits and official deadlines can count days differently, so confirm any legally important date against the governing document. See our full disclaimer.