Construction Working Days Calculator
Site work days excluding weekends, holidays and weather/rain days.
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Construction Working Days Calculator works
The Construction Working Days Calculator counts the days a crew can actually be on site between two dates. It starts from the calendar span you give it, removes weekends according to your work-week pattern, removes the public holidays for the country you select, and then removes any custom dates you add — which on a construction schedule usually means rain days, weather stand-downs, and site-specific closures.
That last step is what separates a construction count from a plain business-day count. A framing or concrete pour lost to weather is not a holiday and not a weekend, but it is still a day the crew could not work, and it still pushes the finish date. Adding those lost days as custom exclusions turns an optimistic calendar-day estimate into a realistic working-day figure you can defend in a progress claim or a delay analysis.
You also control whether the first and last days of the range count, which matters when a contract measures a duration "from" a start date or "to" a completion date. Set the country holiday calendar to the one that governs the job site, not head office, so regional public holidays that shut the site down are excluded correctly.
Worked example
A slab-to-lock-up phase is scheduled from June 1 to June 30 on a Monday-to-Friday week. That span contains 22 weekday dates, but subtract one public holiday and four rain days logged in the site diary and the crew actually had 17 working days available. Booking the phase as "30 days" would have overstated real capacity by almost half — the 17-day figure is what the program and the delay claim should be built on.
Frequently asked questions
How do I account for rain days and weather stand-downs?
Add each lost day as a custom excluded date. The calculator treats those exclusions exactly like holidays — removing them from the working-day total — so your count reflects only the days the crew could realistically be on site, which is the number that matters for progress claims and extension-of-time requests.
Can I use a six-day work week for the site?
Yes. Choose the work-week pattern that matches the site — including Saturday work — and the calculator counts against that pattern instead of a fixed Monday-to-Friday week. Any public holidays and custom rain days you add are still removed on top of the days the pattern already excludes.
Should I include both the start and end dates?
It depends on how the contract measures the period. Use the include-start and include-end toggles to match the contractual wording: a duration counted "from and including" the start date behaves differently from one measured between the two dates, and getting the endpoints right avoids an off-by-one dispute at handover.
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