Business Days CalculatorCalculators
Counts business days between two dates, or adds business days to a date.
Calendar days vs business days: how to count a deadline
A contract that says 30 days, a delivery promised in 5 business days, and a form that reads 35 cal days all count time differently. Know which kind of day you are counting, then count it the same way every time.
The same number of days, two different dates
Calendar days count every day, weekends and holidays included. "Cal days", which turns up in contracts and on forms, is short for calendar days. Business days count only working days, usually Monday to Friday, minus public holidays.
Mix them up and a deadline lands on the wrong date. Ten business days after Friday, September 25, 2026 is Friday, October 9, 2026. Ten calendar days after the same Friday is Monday, October 5. A payment term, a return window, or a notice period counted the wrong way can cost a fee or a right.
Count working days with the Business Days Calculator
The Business Days Calculator has two modes. Count business days between two dates walks through every date in the range, counting both ends unless you untick them. Add business days to a date steps forward or back from a start date, which itself is not counted, until it reaches the number you entered.
Saturday and Sunday are the default weekend, with a Friday-Saturday preset and the option to tick any days. There are no built-in national holiday calendars, so add the public holidays in your range yourself. From Monday, September 7 to Friday, September 18, 2026, with both ends counted, there are 10 business days.
Count calendar days and business days
- Read the wording. "Days" or "calendar days" counts every day. "Business days" or "working days" skips weekends and holidays.
- Check whether the start day counts. The calculator's add mode does not count it, and some contracts spell out their own rule.
- For calendar days, add the number to the start date with weekends included.
- For business days, open Add business days in the Business Days Calculator, enter the start date and the number, and pick the weekend days.
- Add any public holidays in the range to the holiday list, then read the resulting date and weekday.
Where the count can still be off
- Only the holidays you add are excluded. Public holidays differ by country and often by region.
- Half days and custom working hours are not supported. Each business day counts as a full day.
- A contract can define days in its own way. When the wording is unclear, the contract decides, not the calculator.
Frequently asked questions
What does cal days mean?
Calendar days. Every day counts, including weekends and holidays.
What is 35 calendar days from April 13?
May 18. April has 30 days, so 17 days takes you to April 30 and the other 18 land on May 18.
Are business days Monday to Friday?
Usually. Some countries have a Friday-Saturday weekend, and public holidays are not business days either.
How do I count 10 business days from a date?
Skip the start date, then count forward only weekdays that are not holidays. From Friday, September 25, 2026, that lands on Friday, October 9, 2026.
Related tools
Tools used in this guide
