How to Count Business Days Between Two Dates

Counts the working days between two dates, excluding Saturdays and Sundays and counting both end dates. Public holidays vary by country and year, so their number is entered and subtracted.

This tool counts the working days between two dates, leaving out Saturdays and Sundays. It is what delivery dates, lead times and the turnaround on paperwork come down to. Both end dates are counted.

B=TSHB = T - S - H

Here TT is the number of calendar days counting both ends, SS the Saturdays and Sundays among them, HH the number of holidays and BB the business days.

Counting the weekend days

Every complete week contains exactly two weekend days. Dividing the span by seven gives the number of complete weeks, and twice that is most of the answer. Only the leftover days need looking at individually, walking forward from the weekday of the start date. However many years the span covers, the work never exceeds one week's worth.

Worked example

From 1 August 2026 to 31 August 2026, with one holiday, the answer is 20 business days. The span is 31 calendar days counting both ends, of which 10 are Saturdays or Sundays.

1 August 2026 is a Saturday. Thirty-one days make four complete weeks and three days over, so the weekend count is 4 × 2 = 8 plus two more from the leftover Saturday, Sunday and Monday, giving 10. That leaves 31 − 10 − 1 = 20.

Why holidays are entered by hand

Public holidays differ from country to country, and within one country they move from year to year, some of them depending on which weekday a fixed date happens to fall on. A built-in table would quietly give wrong answers the moment it fell out of date. Entering the count instead keeps the tool correct for any country and any year.

Points to watch

Where Saturday is a working day this calculation will not fit. Subtract only the Sundays and the holidays from the calendar days in that case.