"Delivered within 5 working days" sounds simple, until the order is placed on a Friday afternoon and it's not obvious whether that Friday counts, whether the weekend counts, or whether the public holiday next Monday pushes everything back a day. Run the math the naive way — just add 5 to the calendar date — and the estimate lands on a Wednesday. Count it correctly and it actually lands two days later, on the following Friday. That two-day gap is exactly the kind of error that turns a "why hasn't this shipped yet" complaint into a support ticket.
The same counting problem shows up in contracts, payroll runs, visa processing windows, and any deadline written in "business days" instead of a fixed calendar date. A working day isn't a fuzzy concept — it has a precise, consistent definition. What trips people up is that the definition depends on two variables that change by country and company: which two days count as the weekend, and which specific dates are blocked out as holidays. Get either variable wrong and the final date quietly shifts, often without anyone noticing until the deadline is missed.
A working day is any standard business day, Monday through Friday, that is not a recognized public holiday. Saturdays, Sundays, and holidays are excluded from the count. Because most terms start counting from the day after the request rather than the request date itself, "5 working days" from a Monday typically lands the following Monday — six calendar days later, not five, once the weekend in between is skipped.
What is a working day, exactly?
A working day, also called a business day, is a day on which normal business activity happens — banks are open, offices are staffed, and deliveries are processed. In most Western countries that means Monday through Friday, with Saturday and Sunday treated as the weekend and excluded from any working-day count. Three things determine whether a given calendar date qualifies:
- Standard weekdays. Monday to Friday, unless a specific day is a declared public holiday.
- Public holidays. National or regional holidays are removed from the count even though they fall on a weekday.
- Regional weekend variation. Several countries, including many across the Middle East, use a Friday–Saturday or Thursday–Friday weekend instead of Saturday–Sunday, which shifts which weekdays actually count.
Everything else — SLAs, shipping windows, contract clauses, payroll cycles — builds on top of this one definition. The confusion almost always comes from applying the wrong weekend pattern or forgetting to remove a holiday, not from the definition itself. The diagram below walks through a concrete case: an order placed on a Friday, with delivery promised in "5 working days."
The weekend sitting in the middle of the count is what causes the gap — two calendar days pass without moving the working-day total forward at all. Stretch the same logic across a longer window, like a 10-working-day notice period, and two full weekends get skipped instead of one, which is why a "10-day" deadline written in working days almost always lands closer to 14 calendar days out.
of the calendar doesn't count toward a working-day total. That's why any deadline of a week or more runs roughly 40% longer in calendar days than the working-day number implies — before a single holiday is even factored in.
rebrixe.com/blogs/working-days-explainedWhy the definition matters
Getting "working day" slightly wrong doesn't usually cause an error message — it just quietly produces a date that's off by a day or two, which shows up in a few predictable places:
- Shipping and delivery estimates. "Ships in 3 working days" placed on a Friday actually arrives the following Wednesday, not Monday, since the weekend doesn't count toward the total.
- Contracts and notice periods. Legal notice periods and cancellation windows — resignation notice, lease termination, tenancy deposit returns — are frequently written in working days specifically so weekends don't shrink the time a party has to respond.
- Payroll and bank transfers. ACH transfers, international wires, and payroll runs often quote "1–2 working days," which can mean anywhere from one to four calendar days depending on where a weekend or holiday falls in that window.
- Visa and government processing times. Processing windows published in working days — a "15 working day" visa turnaround, for instance — can look much shorter than the real calendar wait, especially around holiday-heavy months like late December.
- SLA and support-ticket deadlines. A "respond within 2 business days" service-level agreement resets differently depending on whether a ticket lands on a Thursday versus a Monday, which affects whether a breach has actually occurred.
Step-by-step: counting working days correctly
Method 1: Manual counting
- Identify the start date. Confirm whether the count begins on the start date itself or the next calendar day — most shipping and legal terms begin counting from the day after.
- Confirm the weekend pattern. Check whether the relevant country or company uses a Saturday–Sunday weekend or a different pattern, since this changes which days get skipped.
- List any holidays in range. Pull the public holiday dates that fall between the start date and the likely end date.
- Count forward, skipping non-working days. Move one day at a time from the start date, skipping weekends and listed holidays, until the required number of working days has been reached.
- Confirm the landing date. The last day counted, after all skips, is the final working day in the range.
Method 2: Using a spreadsheet formula
-
Use NETWORKDAYS to count working days between two known dates.
=NETWORKDAYS(A2,B2)
-
Use WORKDAY to find a date a set number of working days ahead.
=WORKDAY(A2,5)
-
Add a holiday range to either formula to exclude specific dates in addition to weekends.
=WORKDAY(A2,5,D2:D10)
-
Use NETWORKDAYS.INTL for a non-Saturday–Sunday weekend by passing a weekend code — 1 is the default Sat/Sun, 7 is Sunday-only, and 11–17 map to single-day weekends.
=NETWORKDAYS.INTL(A2,B2,7,D2:D10)
The weekend-code argument is the part most templates leave out, and it's exactly the piece that breaks a working-day count for a Friday–Saturday or Thursday–Friday weekend business. Without it, the formula silently assumes Saturday and Sunday are the non-working days even when they aren't.
Common mistakes when counting working days
1. Counting the start date as day one
Most working-day terms begin counting from the day after the starting event, so treating the start date itself as the first working day quietly shortens the count by one full day. An order placed at 11pm on a Tuesday and one placed at 9am on a Tuesday are usually treated identically — the count starts Wednesday either way, not partway through Tuesday.
2. Assuming Saturday and Sunday are always the weekend
A count built for a Saturday–Sunday weekend will be wrong in any country or business that actually observes a Friday–Saturday weekend, which is standard across much of the Gulf region, or a Thursday–Friday weekend, used in parts of the Middle East and South Asia. A courier estimate calculated with the wrong weekend pattern can be off by an entire extra day without any other part of the calculation being incorrect.
3. Forgetting to remove public holidays
A holiday that falls on what would otherwise be a normal weekday still has to be skipped, and missing even one holiday shifts every date after it by a day. This is where "working days" calculators that only account for weekends fall short — they'll confidently return a landing date that's wrong by exactly the number of holidays inside the range.
4. Treating "working days" and "calendar days" as interchangeable
A "5-day" estimate that's actually calendar days will land noticeably earlier than a "5-day" estimate that's actually working days — as much as two calendar days earlier in a single week, and more if a holiday is involved. Mixing the two up is one of the most common sources of missed-deadline disputes in shipping and contract terms, precisely because both get shortened to "5 days" in casual conversation.
5. Ignoring partial or half-day holidays
Some countries and companies treat certain dates — Christmas Eve, New Year's Eve, the day after Thanksgiving — as half working days rather than full holidays. Whether a half day counts as a full working day, a skipped day, or something in between depends entirely on the specific policy or jurisdiction, so it's worth checking rather than assuming.
Real-world examples
A few common scenarios and how the working-day count actually plays out once weekends and holidays are accounted for.
Regional weekend patterns change every one of these examples. The table below shows how the working week shifts depending on which two days a country or company treats as non-working.
Working days vs calendar days vs weekend days
A side-by-side look at how each day type behaves in a typical count.
| Factor | Working day | Calendar day | Weekend day |
|---|---|---|---|
| Counted in "business days" terms | Yes | Only in calendar-day terms | No |
| Includes weekends | No | Yes | Is one |
| Excludes public holidays | Yes | No | No |
| Best for | SLAs, shipping, notice periods, payroll | Invoice due dates, age, fixed-length contracts | Identifying days to exclude from a count |
Skip the manual count: free working days calculator
Manual counting works fine for a single short deadline, but it gets error-prone fast once holidays, regional weekends, or multi-week notice periods are involved. If a deadline just needs a real date, the Rebrixe Working Days Calculator handles the weekend pattern and holiday exclusions automatically: enter a start date and a number of working days, and get the exact landing date instantly, right in the browser.