Business Days Calculator
Count or add working days using weekend patterns and holiday dates you control.
Runs in your browser · No sign-up required
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How this calculator works
Count working days with Saturday–Sunday or Friday–Saturday weekends and holidays you enter as YYYY-MM-DD. Range counts let you include or exclude each endpoint. Adding or subtracting a whole number of working days starts after or before the starting date.
Example
With Saturday–Sunday weekends, 2026-10-02 + 1 working day = 2026-10-05. Entering 2026-10-05 as a holiday moves the result to 2026-10-06.
This static launch build uses weekend rules and user-entered holiday dates; it does not claim an official national holiday dataset.
Does adding one working day count the start?
No. With Saturday–Sunday weekends, Friday 2026-10-02 + 1 working day is Monday October 5, or Tuesday October 6 if October 5 is an entered holiday. Range counting is different: October 5–9 with both endpoints included and October 7 entered as a holiday gives 5 included calendar dates − 0 weekend dates − 1 holiday on a remaining weekday = 4 working days.
This table scrolls horizontally on small screens.
| Start date + working-day count | Entered holiday date | Final date; Sat–Sun weekends |
|---|---|---|
| 2026-10-02 + 1 | — | 2026-10-05 |
| 2026-10-02 + 1 | 2026-10-05 | 2026-10-06 |
A mistake to avoid
The range metrics count only dates within your endpoint choices. Weekends are removed first; duplicate holidays, weekend holidays and dates outside the range do not remove another working day. Use a calendar-day difference for elapsed date gaps, or working-day addition for an eligible future date.
Sources and limits
Calculation methodology · 2026-10-12
Frequently asked questions
Are national holidays included automatically?
No. Enter the holiday dates that apply to your calculation. Invalid dates are rejected, and duplicate dates are counted once.
Does adding one day count the starting date?
No. It moves to the next working day. Range counting is separate: its start and end inclusion switches control whether those dates count.