Business Days Calculator
Add or subtract business days from a date, or count working days between two dates.
How is business days calculator worked out?
Business days are weekdays, excluding Saturdays and Sundays. Adding business days to a date means counting forward one weekday at a time and skipping weekends, which is why ten business days is usually fourteen calendar days.
Business Days Calculator
Resulting date
14 September 2026
- Calendar days spanned
- 14 days
- Weekend days skipped
- 4 days
Show the working
| Start date | 31 August 2026 |
| Add 10 business days | 10 days |
| Resulting date | 14 September 2026 |
Weekends are excluded. Public holidays are not — they differ by country and region, so subtract any that fall in the range yourself.
Business days matter wherever a deadline depends on someone actually being at work: approval windows, notice periods, dispute deadlines and delivery commitments. This calculator excludes weekends. It does not know your public holidays, which differ by country and often by region — subtract those separately.
The formula
Adding: step forward one calendar day at a time, counting only Monday to Friday, until the required number of business days has passed.
Counting between dates: count each Monday-to-Friday day after the start date, up to and including the end date.Ten business days spans fourteen calendar days when the start is a Monday, and can span up to sixteen when weekends fall awkwardly. That gap is why a "10 working day" turnaround and a "two week" turnaround are not the same promise.
Where business days matter on an invoice
Rarely for the payment term itself — net terms conventionally count calendar days — but often for everything around it. Dispute windows, approval turnarounds, notice before charging a late fee and delivery commitments are all more naturally expressed in working days, because they depend on someone being at a desk. Where you use working days, say so on the document: a term that mixes the two conventions without saying which applies where is a dispute waiting to happen.
Public holidays are the missing variable
This calculator excludes weekends only, because public holidays are neither universal nor stable: they differ between countries, between regions of the same country, and from year to year. For a deadline that genuinely matters, check the calendar of the jurisdiction whose working days govern the contract, and remember that a customer's holidays may not be yours when you are billing across borders.
Frequently asked questions
What is a business day?
A weekday on which businesses and banks normally operate — Monday to Friday, excluding public holidays. Saturdays and Sundays are not business days in most jurisdictions, though the working week differs in some countries.
How many business days are in 30 calendar days?
Usually 21 or 22, depending on which day the period starts and where public holidays fall. Thirty calendar days contain four or five weekends.
Does this calculator account for public holidays?
No, only weekends. Public holidays vary by country and often by region within a country, so subtract any that fall within your range yourself.
Put the number on an invoice
The free invoice generator builds the document around your figures — line items, tax, payment terms — and downloads a print-ready PDF. No signup required.
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