How to Count Business Days in Excel (NETWORKDAYS, WORKDAY & Common Errors)
If what you need is a plain day count — how many working days fall between two dates, or what date lands five business days from now — Excel handles it in a single formula. No MOD, no MEDIAN, no partial-day math. Here's how NETWORKDAYS and WORKDAY work, where they differ from business-hours formulas, and the mistakes that most often throw off the count.
Counting the days between two dates: NETWORKDAYS
NETWORKDAYS(start_date, end_date, [holidays]) returns the number of whole working days between two dates, excluding Saturdays and Sundays:
The detail that trips people up: NETWORKDAYS counts both the start and end date if they fall on workdays. A Monday-to-Friday range returns 5, not 4 — because it's counting calendar days elapsed inclusively, not the gap between them. If you actually want an exclusive count, subtract 1 from the result.
To exclude holidays as well as weekends, pass a range of holiday dates as the third argument:
Custom weekends: NETWORKDAYS.INTL
NETWORKDAYS assumes a Saturday–Sunday weekend. If that's not your organization's schedule — common across the Middle East, where the weekend often falls on Friday–Saturday or Friday only — NETWORKDAYS.INTL lets you specify which days count as weekend using a numeric code:
The third argument is a weekend code — 1 for Sat/Sun (the default), 7 for Friday only, 11 for Sunday only, and so on; Microsoft's documentation lists the full set of 14 preset codes, plus a 7-character string format if none of the presets fit (e.g. "0000011" marks only the 6th and 7th listed days as weekend).
Going the other direction: WORKDAY and WORKDAY.INTL
NETWORKDAYS answers "how many business days are between these two dates?" WORKDAY answers the reverse question — "what date is N business days from this start date?" It's the formula behind most "ships in 5 business days" or "due in 10 working days" calculations:
A negative value for days counts backward instead of forward — useful for "what was the date 3 business days before this deadline?" Like its counterpart, WORKDAY.INTL adds the same weekend-code and holiday arguments as NETWORKDAYS.INTL, so you're not stuck with a Monday–Friday assumption.
The errors that most often throw off the count
- Off-by-one confusion. NETWORKDAYS counts both endpoints inclusively. If your mental model is "days between" (exclusive), the formula will look like it's returning one too many.
- Holiday dates stored as text. If your holiday range was pasted or imported and the cells are formatted as text rather than real dates, Excel won't recognize them as dates to exclude — and it won't throw an error. The formula just quietly returns a number that's too high.
- #VALUE! errors from non-date cells. This usually means one of your start/end date cells contains a date imported as text (common with CSV exports) rather than an actual Excel date serial.
- Dates and times mixed in the same cell. NETWORKDAYS looks only at the date portion and ignores time entirely. A start of 11:59 PM and an end of 12:01 AM the next day still register as spanning two calendar days — even though only two minutes actually elapsed.
Business days vs. business hours — not the same formula
If a plain day count is genuinely what you need, NETWORKDAYS and WORKDAY are usually sufficient on their own — there's no reason to reach for a separate tool. Where they run out of road is exactly the case above: once you need actual elapsed hours, not days — a partial first day, a partial last day, or a precise business-hours window like 9 AM–5 PM — day-counting formulas can't get you there. That's a different formula stack entirely (see our guide on calculating business hours in Excel), or, if you'd rather skip rebuilding the formula, our Single Timespan Calculator and Bulk Spreadsheet Calculator compute Total, Business, Weekend, and Weekday Hours to the minute, with configurable weekend days and optional US/UK holiday exclusion.