Working days between two dates. The Business Days Calculator takes start date, end date, public holidays in the range (weekdays) and returns business days plus calendar days (inclusive), weekdays before holidays. Results update as you type, and the formula is shown under the result so you can repeat it in your own spreadsheet.
Operational metrics turn time and capacity into money. Small improvements in utilisation, cycle time or defect rate compound across every unit produced, so measure them regularly. Use the worked example below to check the maths against your own figures.
How the Business Days Calculator works
Counts Monday to Friday between the two dates, both included, and subtracts the holidays you enter. Use it for delivery promises, notice periods and project plans.
Worked example
With the example values (start date 2026-09-07, end date 2026-10-16, public holidays in the range (weekdays) of 2), the business days is 28; calendar days (inclusive) 40, weekdays before holidays 30. Change any figure above and the result updates immediately; use Copy results to paste the summary into a note or email.
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Frequently Asked Questions
How is business days calculated?
business days = weekdays between the dates (inclusive) − public holidays.
Which figures do I need?
Start date, end date, public holidays in the range (weekdays). Take them from the same period and the same set of accounts or reports so the ratio is consistent, and check the example values as a guide to the units expected.
How do I use this in practice?
Measure the metric for a normal week, set a target, change one thing, and measure again. Operational gains come from many small, verified improvements.
