What is Business Days Calculator?
Business Days Calculator counts the number of Monday-to-Friday working days between two dates, automatically skipping weekends and any custom holidays you specify. It can also add N business days to a start date to find the resulting deadline date.
All date calculations run locally in your browser — no dates are sent to any server.
Calculation Modes
Count Days
Count the working days between a start and end date, excluding weekends and holidays.
Add Days
Start from a date and add N business days to find the resulting deadline or delivery date.
Exclude Dates
Mark specific dates as non-working (public holidays, company shutdowns) for accurate counts.
How to Use Business Days Calculator
Set dates
Pick your start and end dates using the date pickers, or enter a start date and number of days to add.
Add holidays
Enter any additional non-working dates — bank holidays, company days off, etc.
Set inclusion
Toggle whether the start and end dates are included or excluded from the count.
Read result
See total calendar days, weekends excluded, holidays excluded, and net business days.
Common Use Cases
| Scenario | What to Do |
|---|---|
| SLA deadline | Add N business days from today to find due date |
| Invoice net-30 | Count 30 business days from invoice date |
| Project duration | Count working days between start and planned end |
| Notice period | Count business days remaining in notice period |
Tips & Common Mistakes
SLA conventions vary. Some SLAs count the start date (day 0 = today), others start from the next day (day 1 = tomorrow). Check your contract and use the inclusion toggle accordingly.
Regional holidays differ. There is no universal public holiday list — always add your region’s specific holidays for accurate counts.
Related Tools
- Date Difference — count all calendar days between dates
- Date Calculator — add/subtract days, weeks, months
- Week Number Finder — find the ISO week for any date