Business-day calculator

Count working days or add working days while excluding selected weekdays and entered holidays.

1. Enter your values in the labeled fields.
2. Results update automatically as inputs change. Review the result and assumptions.
3. Copy or print your result.

Formula and example

Count dates that fall on an allowed weekday and are absent from your holiday list. With Saturday/Sunday excluded and both endpoints included, Monday October 5 through Friday October 9, 2026 gives 5 working days. Adding 5 working days to October 5 gives October 12 because the start is day zero.

Limits and assumptions

Dates from 1900 through 2200. Enter your own holidays, including observed dates when relevant; none are automatically supplied. Duplicate holidays and holidays on excluded weekdays are excluded once. Counting requires end on or after start; adding accepts negative whole days. At least one weekday must remain working. Date-only arithmetic avoids time-zone and daylight-saving shifts. All processing is local; inputs are not stored or transmitted.