Business days calculator
What is a Business Days Calculator?
Many deadlines are expressed in business days: payment terms, delivery estimates, legal notice periods and support SLAs. Counting them by hand across weekends is error-prone. This calculator counts the working days between two dates, or adds a number of business days to a start date to find the due date.
How to use it
- To count, enter a start and end date and read the number of working days.
- To find a deadline, enter a start date and the number of business days to add.
- Check whether the start and end days are included, as conventions differ.
Worked examples
- From Monday 2 November 2026 to Friday 13 November 2026 there are 12 calendar days but 10 business days, counting both ends.
- An invoice issued on Thursday 29 October 2026 with 5 business days' payment terms is due on Thursday 5 November 2026: Friday, Monday, Tuesday, Wednesday and Thursday.
How the count works
Full weeks contribute 5 working days each, and the remaining days are checked one by one to see whether they fall on Saturday or Sunday. Adding business days steps forward one day at a time and skips weekend days.
Things to check
- Public holidays are country and region specific. Subtract them separately if they fall inside your range.
- Different weekends. Some countries have a Friday-Saturday weekend.
- Inclusive or exclusive. Contracts often say the period starts the day after an event. Read the exact wording.
- Cut-off times. An order received after 5 pm is often treated as received the next business day.
Frequently Asked Questions
What counts as a business day?
Normally Monday to Friday, excluding public holidays. Some regions use a different working week.
Are public holidays excluded?
Weekends are excluded automatically. Public holidays vary by country, so subtract any that fall within your range.
How do I add 10 business days to a date?
Enter the start date and 10 business days. The tool steps forward and skips weekends to give the due date.
Does the count include the start date?
Conventions differ. Check the include options and match them to your contract or policy wording.