Business days: counting working days between two dates
A business day is a standard working day — Monday to Friday, minus public holidays. Here is the quick formula for counting working days between two dates, a couple of worked examples, why holidays change the answer, and a month-by-month table of business days in 2026.
This month
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What counts as a business day
A business day (also called a working day) is any day a normal office is open: Monday through Friday. Saturdays and Sundays don't count, and neither do public holidays. It's the unit behind almost every promise with a deadline — "ships in 3 business days", "refunds take 5–7 business days", "30 days' notice in working days".
The reason businesses count in working days rather than calendar days is fairness: a calendar week always contains two non-working weekend days, so "5 business days" is a full working week regardless of which day you start on.
The quick formula
business days = (whole weeks × 5) + leftover weekdays − holidays
Count the complete weeks in your range, multiply by five, add any leftover Monday-to-Friday days at the ends, then subtract public holidays that fall on a weekday.
The whole-weeks trick works because every seven calendar days contain exactly five weekdays, no matter where the run begins. So a 21-day span is three whole weeks = 15 business days before holidays. The only fiddly part is the leftover days at each end and remembering to drop any holidays.
Worked example: a 10-day span
Suppose something is due 10 calendar days from Monday. Ten days is one whole week (5 business days) plus three more days — Monday, Tuesday, Wednesday — which adds 3, for 8 business days. If a public holiday lands on one of those weekdays, subtract it: 7 business days.
Worked example: "within 5 business days"
An order placed on a Thursday with "ships within 5 business days" counts Friday (1), then skips the weekend, then Monday (2), Tuesday (3), Wednesday (4), Thursday (5) — so it ships by the following Thursday. Notice the weekend silently adds two calendar days to the wait.
Business days per month in 2026
2026 has 261 business days in total — 365 days minus 104 weekend days — before you subtract any public holidays. (1 January 2026 is a Thursday.) Subtract your own country's holidays from the relevant months to get net working days.
Month
Days
Weekend
Business days
January
31
9
22
February
28
8
20
March
31
9
22
April
30
8
22
May
31
10
21
June
30
8
22
July
31
8
23
August
31
10
21
September
30
8
22
October
31
9
22
November
30
9
21
December
31
8
23
2026 total
365
104
261
By quarter: Q1 has 64 business days, Q2 has 65, Q3 has 66, and Q4 has 66 — again, before public holidays. July and December tie for the most working days (23 each) because their weekends fall favourably; February has the fewest (20).
Why holidays change the answer
The Monday-to-Friday count is universal, but public holidays are not — they differ by country, and often by region within a country. A range that crosses a national holiday loses a working day that someone in another country would still count. This is why a shipping estimate from an overseas seller can drift: their working calendar isn't yours.
This page deliberately doesn't bake in any one country's holiday list, because there's no single correct one. To get net working days, take the plain weekday count above and subtract the holidays that apply to you:
List the public holidays in your country (and region, if relevant) that fall inside your date range.
Drop any that land on a Saturday or Sunday — they were never working days to begin with.
Subtract what's left from the weekday count.
Where business days show up
Invoices & payments. "Net 30" is usually 30 calendar days, but bank transfers and clearing are quoted in business days — a payment sent Friday may not clear until mid-week.
Shipping & delivery. Couriers quote transit in business days, so an order placed before a weekend or holiday arrives later than the number alone suggests.
Notice periods & legal deadlines. Contracts and courts often specify "clear business days", which can also exclude the first and last day — read the exact wording.
Refunds & disputes. "5–10 business days" for a refund is a working-week-and-a-bit, not a calendar window.
Count days and quarters too
For the plain calendar-day span between two dates, or how far through the current quarter you are, the calculators on the week.hako.to home page handle date arithmetic in your browser. For the week-number view of the year see the 2026 week calendar, for the quarter breakdown see calendar quarters explained, and for how working days map onto paydays see pay periods explained.
The 2026 figures are fixed weekday counts computed from the calendar. The "this month" line is worked out in your browser; nothing on this page is sent anywhere.