Business Days Calculator
Business days
32
- Calendar days44
- Weekend and holiday days12
The start date is excluded and the end date included, matching how payment and delivery terms are quoted. Public holidays vary by country and year, so enter how many fall in your range rather than relying on a built-in list.
Counting the days that actually count
Contracts, courts, shipping and payroll all quote deadlines in working days, and a working day is not a calendar day. "Ten business days" and "ten days" can be four days apart, which is the difference between meeting a deadline and missing it. This tool works both directions: how many business days lie between two dates, and what date falls a given number of business days from a start.
It is built for anyone quoting or checking a lead time — invoice terms, notice periods, statutory response windows, delivery estimates, and project plans that have to survive contact with a calendar.
A worked example: August into September
From Monday 17 August 2026 to Wednesday 30 September 2026 is 44 calendar days and 32 business days; the missing 12 are the six weekends in between. Tell the tool that one public holiday falls in that range and it reports 31.
Running it the other way makes the gap concrete. Thirty business days from 17 August 2026 lands on Monday 28 September 2026. Thirty calendar days from the same start lands on Wednesday 16 September 2026 — twelve days earlier. If a contract says "within 30 days" and you have been reading it as 30 working days, that is the size of the mistake.
Adding business days never lands on a weekend. One business day after Friday 21 August 2026 is Monday 24 August, and adding a negative number counts backwards under the same rule: five business days before 17 August is 10 August.
The counting convention
The start date is excluded and the end date is included. This matches how payment and delivery terms are quoted in practice — an invoice issued today and due in 30 days is not due today — and it is the convention that makes "same day" equal zero rather than one.
The weekend is configurable rather than assumed, because Saturday and Sunday is a regional convention, not a universal one. Friday and Saturday is standard across much of the Middle East, Sunday-only working weeks exist, and setting no weekend at all turns the tool into a plain calendar counter. Holidays you enter as a count are subtracted from the total after the weekends have been removed.
Why holidays are an input, not a table
The tool deliberately ships without a built-in holiday list. Public holidays vary by country, by state or province within a country, and by year — many move with Easter or fall on the nearest Monday, and several countries add one-off holidays for national events. A hardcoded table would be wrong for most visitors on the day it shipped and wrong for everyone within a couple of years, without ever saying so.
So you count the holidays that apply to you in the range and enter that number. It is one more step, and it is the difference between an answer you can rely on and an answer that looks authoritative. Note that a holiday falling on a weekend should not be counted, since that day has already been excluded — counting it twice would understate the total.
Working day questions
Does "within 5 business days" include the day I sent it?
Under the convention used here, no: the clock starts the following working day. That is the usual reading of commercial terms, but it is not universal — some statutory rules count differently, and a few count from receipt rather than dispatch. Where a deadline is legally significant, check the wording rather than assuming.
What about a holiday that falls on a Saturday?
Do not count it. Saturday has already been removed as a weekend day, so subtracting it again would remove a working day that never existed. If your jurisdiction moves the observance to the following Monday, count that Monday instead.
Why do the two modes give slightly different-looking answers?
They ask different questions. Counting between two dates excludes the start day; adding N business days moves N working days forward from the start. Both are consistent with each other, but the second returns a date and the first returns a count.