Business days calculator — working days between two dates
Count business days between two dates, excluding weekends and your own holiday list. Also works in reverse: find the date that is N working days out.
Free · no signup · runs in your browser·Updated
Short answer
Business days between two dates are the calendar days in the range, minus weekend days, minus any holidays that fall on a working day. From 2026-01-05 to 2026-03-31 inclusive that is 86 calendar days, 24 weekend days and 2 holidays, leaving 60 working days. Switch the weekend rule to Friday and Saturday and the count changes.
This business days calculator counts working days between two dates. It takes the calendar range, removes the weekend days you nominate, then removes any holiday you paste in that would otherwise have been a working day. Dates go in as YYYY-MM-DD.
The second mode runs it the other way: give it a start date and a number of business days, and it returns the date you land on together with how many weekends and holidays it stepped over on the way.
Your numbers
What are you counting?
Written as YYYY-MM-DD. Read literally — no timezone conversion.
Written as YYYY-MM-DD.
Range boundary
Match the site doing the work, not the site running the report.
One YYYY-MM-DD date per line. Lines starting with # are comments. Use observed dates, not actual dates.
Result
Working days in the range
60 days
2026-01-05 to 2026-03-31 · both dates counted
Calendar days in the range86
Weekend days removed (Saturday + Sunday)24
Holidays removed2
Holiday dates ignored (weekend or out of range)3
Five-day weeks equivalent12.0
Working share of the range69.8%
range 2026-01-05 → 2026-03-31 (end date included)
calendar days = 86
− weekend days (Saturday + Sunday) = 24
− holidays on a working day = 2
working days = 60
60 working days, spread across 86 calendar days. 26 days are not worked, so anything you schedule as 60 working days occupies 86 days of the calendar.
Everything is computed in your browser. Nothing you type is sent anywhere or stored.
The formula
Working days = Calendar days in range − Weekend days − Holidays that land on a working day
Calendar days in range
Every day from the start date to the end date. Inclusive counting adds one to the day difference.
Weekend days
Days matching your weekend rule. Saturday and Sunday by default; Friday and Saturday in much of the Middle East.
Holidays that land on a working day
Dates from your holiday list that fall inside the range and are not already a weekend day. A holiday on a Sunday is not subtracted twice.
Order matters. Subtract weekends first, then holidays, otherwise a public holiday that falls on a Saturday gets counted twice and your answer is a day short. The calculator does it in that order and reports how many holiday lines it ignored.
Worked example
Start date
2026-01-05
End date
2026-03-31
Range
Inclusive of both dates
Weekend
Saturday + Sunday
Holidays pasted
5 dates
Result
60 working days out of 86 calendar days
The range holds 86 calendar days. It starts on a Monday and covers 12 whole weeks plus two days, so 24 of those days are weekend days, leaving 62. Two pasted holidays (2026-01-19 and 2026-02-16) fall inside the range on a Monday, so 60 working days remain. The other three pasted dates sit outside the range and are ignored.
How this business days calculator counts working days
Three subtractions, in a fixed order. Count the calendar days in the range. Remove the days that match your weekend rule. Remove the holidays that survived step two. Whatever is left is working days, and that is the number your lead times, SLAs and close calendars are really denominated in. The gap between the two units is bigger than people expect: ten business days is fourteen calendar days, and thirty business days is forty-two.
Setting
Usually counted in
What goes wrong when the unit is wrong
Payment terms (net 30)
Calendar days
Sales says "30 days", the customer hears working days, and the invoice ages 42 calendar days before anyone calls it late.
Supplier lead time
Business days
A 10-day quoted lead time loaded as 10 calendar days makes every reorder point four days short of cover.
Month-end close tasks
Business days
A close calendar built on calendar-day offsets puts "day 3" on a Saturday whenever the month starts late in the week.
Dunning and reminder ladders
Business days
Calendar-day offsets fire reminders on weekends, so the first thing the customer sees is already stale.
Support SLA response
Business days
The contract says business days and the ticket clock counts hours, so breaches get reported that never happened.
The same number means two different things depending on which unit the field is in.
Inclusive or exclusive: the off-by-one that costs a day
Counting inclusively means both the start and end date are in the range — the natural reading of "how many working days do I have between Monday and Friday?" (five). Counting exclusively drops the end date, which is what date-difference functions in most databases and spreadsheets do (four).
Neither is wrong. What breaks things is mixing them: an SLA measured inclusively against a report built on an exclusive date difference will disagree by exactly one day, forever, and the argument about who is right takes longer than fixing it.
Holiday lists are where the count goes wrong
A holiday on a weekend is not an extra day off. If you subtract it separately you lose a working day that never existed.
Observed dates, not actual dates. When a holiday falls on a Saturday and the office closes the Friday before, the Friday is what belongs in the list.
Regional holidays. A single company-wide list gives one wrong answer to every site. Keep one list per calendar and pick the one that matches the site the work happens at.
Half days. Business-day counting has no half. Either it is a working day or it is not; decide once and write it down.
Stale lists. Moving holidays shift every year. A list copied from last year quietly makes every lead-time calculation wrong from January.
Working days from a date
The forward mode answers the promise-date question: a purchase order placed on 2026-01-05 with a 10 business-day lead time arrives on 2026-01-20, fifteen calendar days later, because the count steps over four weekend days and one holiday. Enter a negative number to walk backwards and find the date work has to start.
Pair it with the manufacturing lead time calculator when the promise date depends on shop-floor queue and run time rather than a supplier quote, and with the fiscal period calculator when the deadline is a close task rather than a delivery.
Getting this out of an ERP is the awkward part: holiday tables live in one place, the working calendar in another, and the report that needs both is a saved search with a formula field. With ERPray you ask for it in words — "open POs where the promised date is fewer than five working days away" — and the query it ran is shown underneath so you can check which calendar it used.
Frequently asked questions
How many business days are between two dates?
Count every calendar day in the range, subtract the days matching your weekend rule, then subtract the holidays that are left over. From 2026-01-05 to 2026-03-31 inclusive: 86 calendar days, minus 24 weekend days, minus 2 holidays, gives 60 business days. Decide up front whether the end date counts.
Do business days include holidays?
No. A business day is a day the business is open, so public holidays and company shutdown days come out of the count. Only holidays that fall on a day that would otherwise have been worked reduce the total — a holiday on a Sunday changes nothing, because Sunday was already excluded.
Is the start date counted as a business day?
When you are counting the days in a range, yes, if you are counting inclusively. When you are adding business days to a date, no: day one is the next working day after the start date. That is why "5 business days from Monday" lands on the following Monday, not Friday.
What counts as a weekend?
Saturday and Sunday in most of the world. Friday and Saturday is standard across much of the Middle East, and some markets run a six-day week with Sunday as the only day off. Pick the rule that matches the site doing the work, not the site running the report.
How many business days are in a year?
2026 has 261 weekdays — 365 days less 52 Saturdays and 52 Sundays. Subtract your holiday list to get usable working days. The figure moves by one or two days a year depending on which weekday 1 January lands on and whether the year is a leap year.
Why does my ERP give a different business day count?
Usually one of three reasons: it counts exclusively while you counted inclusively, it is using a holiday calendar assigned to a different subsidiary or site, or the lead-time field it read is stored in calendar days. Check the boundary rule first — a difference of exactly one day is almost always that.
This calculator needs you to find the inputs first. ERPray pulls them from your own ERP account and computes the answer live — with the exact query shown so you can check it.