What counts as a working day here
The first calculator looks at every date from the start date to the end date, both included. Saturdays and Sundays come out first. Then each holiday you typed in the holiday box, one date per line, comes out if it falls on a weekday inside the range. A holiday that lands on a weekend is not subtracted twice: it stays in the weekend days figure and is left out of “Holidays on weekdays”.
The second calculator works from a start date. The start date itself is not counted; the next Monday-to-Friday date is working day 1, and Saturdays, Sundays and every date in the holiday box above are stepped over. A negative number counts back instead. The holiday box is the only holiday information it has, so list every holiday the period covers.
Formulas
Both counts are exact. Their accuracy depends on the holiday list: any holiday you leave out is counted as a working day.
Weekends and holidays vary by country
The calculator assumes a Monday-to-Friday working week with Saturday and Sunday off. That is common but not universal: in some countries the weekly rest days fall elsewhere, and many businesses work a six-day week. If your weekend is different, this calculator will give the wrong count.
Public holidays differ between countries and often within one. The United Kingdom alone publishes separate bank holiday lists for England and Wales, Scotland and Northern Ireland. Many places also move a holiday that falls on a weekend to a weekday: in the UK, Boxing Day 2026 falls on a Saturday, so the bank holiday is on Monday, December 28. The calculator holds no holiday calendar, so type the dates that apply to you, including any substitute days.
Worked examples
- October 1 to 31 is 31 dates, both ends included.
- October 2026 has 5 Saturdays and 4 Sundays: 9 weekend days.
- 31 − 9 = 22 working days.
- The range covers 19 dates, of which 15 are Monday to Friday.
- The holidays entered are 2026-12-25, 2026-12-28 and 2027-01-01, all weekdays.
- 15 − 3 = 12 working days.
- Working days 1 to 3 are October 14, 15 and 16.
- Skip the weekend of the 17th and 18th; days 4 to 8 are October 19 to 23.
- Skip the next weekend; days 9 and 10 are October 26 and 27.
- With no holidays listed, day 10 is Friday, January 1, 2027, itself a public holiday in many countries.
- Enter 2026-12-25, 2026-12-28 and 2027-01-01 in the holiday box. Each one falls on a weekday inside the period, so each pushes the deadline one working day later.
- Three more working days after January 1 are January 4, 5 and 6, so the deadline becomes Wednesday, January 6.
How “within 10 business days” is counted
Rules written in contracts, laws and service terms do not all count the same way. Some treat the day a request arrives as day zero, as the second calculator does; others count it as day 1. Some end a deadline at the close of business on the last day, others at midnight. The two calculators here show the difference: 10 working days after October 13 is October 27, yet counting October 13 to 27 with both ends included gives 11 working days. Check the wording of the rule that applies to you before relying on either number.
Easy ways to miscount working days
- Leaving out holidays. The count is only as good as the holiday list. A month with two public holidays has two fewer working days than the calculator shows without them.
- Forgetting substitute days. When a holiday falls on a Saturday or Sunday, the day off often moves to a weekday. Enter the substitute date, not the original one.
- Counting the start date twice. A range that includes the start date and a deadline count that excludes it differ by one, as in the October example above.
- Using the wrong weekend. Where the weekend is Friday and Saturday, both results here will be off, because Sunday is a working day there.
Type holiday dates as year-month-day, for example 2026-12-25, so that day and month cannot be read the wrong way round.
Sources
- UK bank holidays, GOV.UK.