Business Days Calculator

businessDays = totalDays − weekendDays, where totalDays runs from the day after the start date through the end date

startDate

The first day, which is not counted — the span starts the next morning

endDate

The last day, which is counted

weekend

Which weekdays are rest days: Saturday and Sunday, Sunday only, or Friday and Saturday

businessDays

Days in the span that are not rest days

weekendDays

Days in the span that are rest days

totalDays

Every day in the span, rest days included

Use it to quote a delivery window, to work out how many weekdays a notice period covers, or to check a project length that was quoted in days rather than weeks. The counting convention is the one the date calculator uses: the start date is not counted and the end date is, so a span of one day is zero and a full year is 364. Public holidays are not deducted. They change every year and are set by governments, so the number here is a ceiling on working days rather than the final answer.

1. The whole of 2026, with Saturday and Sunday off

   1. The span is 364 days: 2026 has 365, and the start date is not counted while the end date is
   2. 364 is exactly 52 weeks, so every weekday appears 52 times inside the span
   3. Saturday and Sunday therefore account for 104 rest days, leaving 260 working days
   4. The three outputs always balance: 260 + 104 = 364

   Because 364 is a whole number of weeks, all three weekend rules give the same 260 here. The next example is where the choice starts to matter.

2. January 2026, resting on Sunday only

   1. The span is 30 days: January has 31, minus the first one, which is not counted
   2. Four Sundays fall inside it — the 4th, 11th, 18th and 25th
   3. Those four are the only rest days, so 30 − 4 = 26 working days
   4. The same month under the Saturday-and-Sunday rule gives 21, five fewer

   Resting one day instead of two adds five working days to a 30-day month. For anyone on that schedule, a tool with a hard-coded weekend would be wrong every single time, and the page would look perfectly normal.

3. January 2026, resting on Friday and Saturday

   1. The span is the same 30 days, so totalDays does not move
   2. Five Fridays (2, 9, 16, 23, 30) and five Saturdays (3, 10, 17, 24, 31) fall inside it
   3. Ten rest days leave 20 working days
   4. That is one rest day more than the Saturday-and-Sunday rule gives in this particular month, because January 2026 contains a fifth Friday and a fifth Saturday

   Friday and Saturday is the weekend across much of the Middle East. Which of the three rules yields more rest days depends entirely on where the month falls, so the answer cannot be guessed — it has to be counted.

Public holidays are not counted and cannot be: they are set by each government and announced roughly a year in advance, so any list baked into a tool has a silent expiry date. Treat this number as an upper bound and subtract the holidays that fall inside your span. Weekends are all the rule covers, and the three offered are the ones in common use — a four-day week, a rotating roster or a half-day Friday needs a different calculation.

How many business days are in a year?

Roughly 260 under a Saturday-and-Sunday weekend, and it moves by a day or two with the calendar. Counting 1 January to 31 December gives 364 days, which is exactly 52 weeks, so every weekday appears 52 times and 260 of them are working days. Whether the excluded 1 January is itself a working day depends on which weekday it lands on.

Do you count the start date?

The start date is not counted and the end date is, so a single day gives zero and a full year gives 364. That is the same convention the date calculator uses, which is why the two pages agree when the same pair of dates is entered into both.

What about public holidays?

They are not deducted, and the tool does not try. Public holidays are set by each government and published about a year ahead, so a list built into a calculator would go quietly stale. Subtract them yourself, or look up the official calendar for the country — the references below link to the ones for the United Kingdom and the United States.

Which weekend rule should I pick?

Saturday and Sunday for most of Europe and the Americas. Sunday only suits the parts of Asia where a six-day week is still normal, and Friday and Saturday covers much of the Middle East. The choice is not cosmetic: in a 30-day month it moves the answer by five working days, and nothing on the page would look wrong either way.

Can I put the later date first?

Yes, the two dates are swapped when the second one is earlier, and the count is identical either way. A span of working days has no direction, so there is no signed version of it to report.

• UK bank holidays — UK Government
• Federal holidays — US Office of Personnel Management
• Public holidays and religious affairs — Government of the United Arab Emirates