Last updated: 2026-06-22

Business Days Between Two Dates

A business day is conventionally defined as any weekday — Monday through Friday — that is not a public holiday. Counting business days between two dates is a routine task in contract law, project management, regulatory compliance, and financial settlement.

How the count works

This calculator counts all weekdays (Monday–Friday) from the start date to the end date, inclusive of both endpoints, and subtracts any weekday public holidays entered by the user. Weekend days (Saturday and Sunday) are excluded from the weekday count automatically.

The formula in outline:

where the interval is closed on both ends.

Public holidays

Public holidays are not deducted automatically because they vary by country, region, and jurisdiction. A date that is a national holiday in one place is an ordinary working day in another. The "public holidays" field lets you enter the number of weekday holidays that fall within the selected range so the calculator can subtract them accurately.

Calendar days and weekend days

The calendar days output is the straightforward count of all days in the range, inclusive. The weekend days output is the number of Saturdays and Sundays in the range. Together, the three outputs satisfy:

(where holidays is the value you entered).

Common uses

Business-day counts appear in a wide range of contexts: payment terms (net 30 business days), regulatory response deadlines, project timelines, and legal notice periods. Many contracts specify business days rather than calendar days precisely because weekends and holidays interrupt normal operations.

For finding the ISO week number of a specific date, see ISO Week Number Calculator. For a general calendar-day difference in years, months, and days, see Date Difference Calculator.