Deadlines, delivery times, notice periods and payment terms are often stated in business days. Weekends and public holidays don’t count, so 10 business days usually means two calendar weeks. Holiday calendars differ by country and region – enter how many fall in your period.
How to use the Business Days Calculator
- Start date
- End date
- Working week
- Include end date
- Public holidays on working days
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the start and end dates, choose a 5- or 6-day working week, whether the end date counts, and the number of public holidays on working days.
Tips
- Check whether the end date should be included – event durations usually include it, elapsed time does not.
- Months have 28–31 days, so “one month” is counted by calendar date, not as 30 days.
- Use 24-hour time or set AM/PM carefully when entering clock times.
- Time zones and daylight-saving changes are not applied unless the calculator says so.
Common mistakes to avoid
- Counting a 30-day month when a calendar month is meant (or the reverse).
- Forgetting leap years when counting days across February.
- Mixing decimal hours (7.5 h) with clock time (7:30).
Inputs explained
| Field | What to enter |
|---|---|
| Start date | A date |
| End date | A date |
| Working week | Choose one: 5 days (Mon–Fri), 6 days (Mon–Sat) |
| Include end date | Choose one: No, Yes |
| Public holidays on working days | A number |
What each result means
- Calendar days = [End date] – [Start date] + [Include end date]
- Weekend days = [Calendar days] – [Business days] – [Public holidays on working days]
- Working weeks = [Business days]÷[Working week]
Formula
Business days = days in the period that fall on working days − public holidays5-day week: Monday–Friday; 6-day week: Monday–SaturdayWorked example
Inputs — Start date: 2026-10-25; End date: 2026-11-24; Working week: 5 days (Mon–Fri); Include end date: Yes; Public holidays on working days: 0.
Results — Calendar days = 31; Business days = 22; Weekend days = 9; Working weeks = 4.4.
Frequently asked questions
How many business days are in a month?
About 20–23 for a Monday–Friday week, before holidays.
Is Saturday a business day?
In most countries no, but some businesses and countries work a six-day week.
Does "within 5 business days" include today?
Usually not – counting starts the next business day.
What formula does the Business Days Calculator use?
Business days = days in the period that fall on working days − public holidays.