Construction Shutdown Calculator
Net working days inside a date range after subtracting industry shutdowns.
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Construction Shutdown Calculator works
The Construction Shutdown Calculator counts the net working days inside a date range once the closures come out. It removes weekends and public holidays like any business-day count, and then lets you add each industry shutdown day — a Christmas-New Year break, a builders' holiday week, a site-specific dark stretch — as a custom exclusion, treating the shutdown exactly like a run of holidays and pulling it out of the total.
A shutdown is not a statutory holiday, so a generic calendar never removes it — but it takes working days off the program just as surely, often several weeks at a time. Layering the shutdown dates on top of the ordinary weekend-and-holiday exclusions is what turns a raw weekday span into the number of days a crew can genuinely be on site.
Apply the public-holiday set for the jurisdiction that governs the site, which may differ from where head office sits, and mind the endpoints: contracts measure durations inconsistently, so decide whether the first and last day of the range count and set the calculation to match the contract wording. The result is a general-information count for planning and record-keeping, not a contractual determination.
Worked example
A fit-out phase scheduled December 1 to January 15 on a Monday-to-Friday week holds roughly 34 weekday dates. Remove the Christmas and New Year public holidays and then the industry shutdown from December 22 through January 2, and the working days that survive drop into the low twenties — booking the phase against the 34-day weekday count overstates real capacity by more than a third, and the whole overstatement sits in the two weeks nobody was going to work.
Frequently asked questions
How is a shutdown different from a public holiday in the count?
Only in where the dates come from. Public holidays are the statutory days the calendar already knows; shutdowns are industry- or site-specific closures nothing generic removes. You enter the shutdown dates as custom exclusions, and the calculator subtracts them exactly like holidays.
Why count net working days instead of the weekday span?
Because durations, cash-flow forecasts, and delay claims all rest on days a crew can actually work. A phase booked as its weekday span but crossing a five-day shutdown commits you to finishing in fewer working days than the schedule admits — a gap that only surfaces once the phase is already late.
Do the start and end dates count as working days?
That depends on your contract, which is why the calculator lets you include or exclude each endpoint. Some contracts count "from and including" the start date, others measure strictly between the two dates — a one-day difference that is a real source of handover disputes. Set it to match the contract wording rather than assuming.
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