Business Days & Working Day Calculator
Count business days between two dates, exclude weekends and holidays, or add/subtract working days from a start date for project and payroll planning.
Business Days Calc — interactive calculator, computed instantly in your browser.
Business Days Calculator: Working Days, Deadlines & Holiday Exclusions
How Weekends Shrink a 30-Day Window
Key Takeaway: A "30-day" payment term is really ~21–22 working days — always confirm whether a contract counts calendar or business days.
A Business Days Calculator counts only Monday–Friday dates while skipping weekends and (optionally) a custom holiday list. Net-30 invoices, project SLAs, payroll cycles, and court filing deadlines almost always count in working days, but most people count calendar days and miss their deadline.
1. Counting Working Days Between Two Dates
The algorithm walks one calendar day at a time from start to end, incrementing a counter only when the day is neither a Saturday nor a Sunday nor a listed holiday:
- Default mode excludes the start date but includes the end date — standard for deadline math.
- Inclusive mode counts both endpoints — used for shift counts and attendance.
- Holidays are parsed from a pasteable YYYY-MM-DD list, so multi-country calendars are supported.
2. Worked Example: Net-30 Invoice
- Invoice issued Friday, October 2 → payment due 30 working days later
- 30 working days ÷ 5 per week = 6 full weeks of weekdays
- Skip every Saturday and Sunday (12 weekend days) plus any listed holidays
- Result: the real deadline lands roughly 42–44 calendar days after issue — not 30
3. Add or Subtract Working Days
In "add" mode, the calculator walks forward (or backward for negative inputs) one day at a time, decrementing a remaining-work-day counter only on valid weekdays. This is how you find "10 business days from today" without manually flipping a wall calendar — including correct handling of month and year boundaries and leap years.
🔗 Scheduling & Deadline Cross-References
Net-30 invoice terms, sprint planning, and payroll cycles all count in working days rather than calendar days. Explore our ⏱️ Date & Time Hub for more scheduling utilities.
Measure elapsed clock time between two timestamps or find your exact chronological age with the tools below.
Frequently Asked Questions (Business Days Calc)
It depends on the convention. The default mode excludes the start date and includes the end date (standard for deadline math), while inclusive mode counts both endpoints. The calculator lets you toggle between the two.
A standard year has 261 weekdays (52 weeks × 5 days + 1) and a leap year has 262. Subtract your country's public holidays (typically 8–13 in the US, 8 in the UK) for actual working days — usually 250–255.
Paste each holiday as YYYY-MM-DD on its own line in the Holidays field. The calculator treats any matching date as non-working regardless of weekday, so holidays falling on weekends are safely ignored.
It skips every weekend and listed holiday, so 10 business days is typically 12–14 calendar days. For shipping estimates, add 1–2 extra days of buffer since carriers may not dispatch on all working days.