Business Days Calculator

Count the days that actually count

Set two dates and the tool counts every working day between them, with the calendar total beside it so you can see what was taken off. Or switch to Add working days and it finds the date a deadline lands on.

The weekend is a setting and the holidays are yours to paste in. Both matter more than they look, and both are covered below.

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Why “business days” needs two settings

The arithmetic is trivial. What makes business-day calculations wrong is that two of their inputs are conventions rather than facts, and a tool that hardcodes either produces a plausible number that happens to be false.

The weekend is not Saturday and Sunday

It is in most of the world, and it is not in a large and economically significant part of it.

Friday and Saturday is the weekend in Egypt, Israel, Jordan, Kuwait, Qatar and Saudi Arabia, among others — the working week runs Sunday to Thursday. Some countries take Thursday and Friday; some take Sunday alone; and plenty of work is scheduled with no weekend at all.

Hardcoding day === Saturday || day === Sunday is the single most common defect in business-day code, and it is off by roughly two days a week for anyone it does not describe. Over a quarter that is more than a fortnight.

Public holidays are local and they move

There is no holiday list built into this tool, on purpose. Holidays vary by country, by state or province, by industry, and by year — many are tied to Easter or to a lunar calendar, and several are “observed” on a different day when they fall on a weekend.

A bundled list would be right for one country in one year and quietly wrong afterwards. Wrong and quiet is the worst combination: the tool keeps answering, and nothing tells you the answer changed.

So you paste your own, one date per line. Anything after a # is ignored, so a list copied from an HR page keeps its labels:

2026-01-01 # New Year's Day
2026-07-03 # Independence Day (observed)
2026-12-25 # Christmas

A line the tool cannot read is named, not skipped. A typo in a holiday list changes the answer with no visible cause, so it says which line it could not use rather than quietly carrying on.

A holiday on a Saturday is not a day off

This is the subtlety that makes many calculators disagree, and it is a one-line rule: a holiday is only subtracted if it falls on a working day.

4 July 2026 is a Saturday. It is a holiday, but it was already not a working day, so removing it from the count would take away a day that was never in it. Add it to the list and this tool leaves the total alone — and tells you it did, by listing only the holidays it actually applied.

Note the separate question of whether your employer observes it on the Friday or Monday instead. That is a policy, not arithmetic. If yours does, list the observed date.

Does the first day count?

The other place calculators disagree, and unlike the weekend it has no correct answer — only two readings, both in use.

Counting the range. “How many working days in July?” means every working day in the period, first and last included. That is the default here, because it is what a from/to date picker implies.

Counting from a trigger. “You will hear within ten business days” means ten days starting tomorrow. The day the clock starts does not count.

The checkbox switches between them, and the Add working days direction always uses the second reading, because that is the only sense in which “ten business days from now” is ever said.

A worked example. From Monday 20 July 2026, ten business days lands on Monday 3 August — a fortnight later, because two weekends fall inside it. People consistently guess the Friday, which is only five days out but is the difference between meeting a deadline and missing it.

What a month is worth

The ratio is more useful than any single answer. A calendar month is 30 or 31 days; a working month is usually 21 to 23.

From 26 July to 25 August 2026 is 31 calendar days and 22 working days — nine days off. December 2026 is 31 calendar days and 23 working days before any holidays, and about 20 after the usual ones.

So a “one month” deadline and a “twenty business days” deadline are roughly the same thing, and a “30 business days” deadline is nearer six weeks than one month. That gap is where scheduling goes wrong.

Counting backwards

Enter a negative number of working days to run the calculation from a deadline instead of towards one — the question that starts “the filing is due on the 30th, when do I need to have it ready?”

Backwards counting uses the same rules, so it also skips weekends and holidays, and it also starts on the day before rather than the day itself.

Where this is not enough

Two limits worth stating.

Half days and part-time weeks are not modeled. A four-day working week can be approximated by choosing a three-day weekend only if the days off are the same every week; anything irregular has to go in the holiday list.

“Business day” is sometimes defined in the contract, and not always as you would expect. Banking days exclude days a clearing system is closed, which is not the same set as public holidays. Court days follow the court’s own calendar. If a deadline matters, the definition that counts is the one in the document, not the one in any calculator.

For plain calendar arithmetic — days, weeks and months with nothing skipped — use the date difference calculator.

Frequently asked questions

How do I count working days between two dates?

Set both dates and the tool counts every day that is not a weekend or a holiday you have listed. It shows the calendar total beside it so the two are easy to check against each other, and names any holidays it actually subtracted.

Does the start date count?

By default yes — a from/to range reads as "the working days in this period". Uncheck Count the start date as well for the other reading, the one a contract means by "within ten business days", where counting begins the following day.

What if my weekend is not Saturday and Sunday?

Change it. Much of the Middle East works Sunday to Thursday, so Friday and Saturday are the weekend; some countries take Sunday only. A calculator that assumes Saturday and Sunday is wrong by two days a week for a large part of the world, which is why this is a visible setting rather than an assumption.

How do I include public holidays?

Paste them into the holidays box, one ISO date per line. Anything after a # is ignored, so a list can keep its labels. There is no built-in holiday list because holidays differ by country, by state and by year — a bundled one would be wrong for most visitors and silently out of date for the rest.

What happens to a holiday that falls on a weekend?

Nothing — and that is deliberate. It was already not a working day, so subtracting it again would remove a day that was never in the count. Only holidays falling on working days are taken off, and the tool lists which ones those were.

When do ten business days from today land?

Switch to Add working days. Counting starts the day after the start date and skips weekends and holidays, so ten business days from a Monday is the Monday a fortnight later. Enter a negative number to count backwards from a deadline.

Will this match my contract exactly?

Only if the settings match its definitions. Agreements differ on whether the first day counts, on which days are holidays, and occasionally on what a business day is at all — some specify banking days, which exclude days a bank is closed for other reasons. Read the clause; use this for planning.