Add Business Days Calculator
Add working days to a date, skipping weekends.
Use a negative number to count backwards
Results update as you type.
How it works
An add business days calculator adds a number of working days to a start date, stepping over Saturdays and Sundays so the result always lands on a weekday. It answers deadline questions phrased in business days — "payment is due 10 business days after invoice," "results within 5 working days," "a 15-working-day processing window" — and reports both the resulting date and how many calendar days the span actually covered. Business days are the natural unit for commercial and legal deadlines because work does not happen at weekends. Counting them by hand is fiddly: you cannot simply add the number of days, because each weekend inserts two skipped days, and long spans can skip several weekends. Miscounting is easy and the cost is real, since a deadline stated in working days that you convert wrongly can be missed by days. The calculator removes that risk by advancing one day at a time and only decrementing the count on weekdays. The calendar-days-spanned figure shows the true elapsed time, which is always longer than the business-day count because of the skipped weekends — 10 business days typically spans 14 calendar days. This tool counts weekends only; public holidays vary by country and are not deducted, so subtract any holidays in your span separately. Accounts teams tracking payment terms, operations staff quoting turnaround times, and anyone working to a working-day deadline use an add business days calculator to find the exact due date.
Step one calendar day at a time from the start date, counting only Mon–Fri, until the required number of business days is reached
Starting from the given date, the calculator moves forward one calendar day at a time. Each time it lands on a weekday (Monday to Friday) it counts one business day toward the target; when it lands on a Saturday or Sunday it moves on without counting. It stops once the required number of business days has been reached, and that date is the result. A negative input steps backwards using the same weekday-only counting. Calendar days spanned is the plain day gap between the start and result dates.
Source:Gregorian calendar / ISO 8601
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter start date and business days to add.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Resulting date updates instantly as you type — no button to press.
Frequently asked questions
What counts as a business day?
This calculator treats Monday through Friday as business days and skips Saturdays and Sundays. It does not account for public holidays, which differ by country and region, so a national holiday falling on a weekday is still counted here as a working day. If your deadline must exclude specific holidays, work out the date with this tool and then push it forward by the number of holidays that fall within the span.
How is this different from adding calendar days?
Adding calendar days counts every day including weekends, whereas adding business days skips Saturdays and Sundays, so the result always lands on a weekday and the span covers more calendar time. Ten business days is about two calendar weeks, not ten days. Many contracts and service commitments are written in business days precisely to exclude weekends, so converting them correctly requires the weekend-skipping this calculator provides rather than a plain day addition.
Why is calendar days spanned larger than the business days?
Because each weekend inside the span adds two days that are not counted as business days but still pass on the calendar. Ten business days usually includes two weekends, so the calendar span is around 14 days. The calendar-days figure tells you the real elapsed time, which is useful for understanding how far ahead a working-day deadline actually is when planning around it in ordinary dates.
Can I count backwards in business days?
Yes. Enter a negative number of business days to step backwards from the start date, skipping weekends in the same way, which answers questions like "what date was 10 working days before this deadline." The result still lands on a weekday. This is handy for back-planning, such as finding the last day to send something so it arrives a set number of working days before an event, allowing for weekends.
Does the start date count as day zero?
Yes. The start date itself is not counted as a business day; counting begins on the next weekday. So adding one business day to a Friday gives the following Monday, not the Friday. If your rule counts the start date as the first business day, subtract one from the number you enter. Whether the start day counts depends on the wording of your deadline, so check the terms you are working to.