How to Calculate Working Days Between Dates Excluding Holidays

A project manager once asked me how many working days were left in a quarter for a contractor billing dispute. I counted on my fingers, got it wrong by three days, and learned the most important lesson in date arithmetic: never count working days by hand. Excel has a function for it, and it takes about thirty seconds once you know the setup.

The function: NETWORKDAYS

=NETWORKDAYS(start_date, end_date, [holidays])

NETWORKDAYS counts the weekdays (Monday to Friday) between two dates, inclusive of both endpoints, then subtracts any dates that appear in your holidays list. Weekends are always Saturday and Sunday; that part is not configurable. If you need different weekends, there is a variant below.

Worked example: September 2026

Wait, check that: September 7, 2026 is Labor Day, a Monday, so the raw weekday count of 23 drops to 22 when you pass the holiday list. Which brings us to the part everyone gets wrong.

Feed it a real holiday list

The third argument is a range or array of dates to exclude. Put your holidays in a column, say H5:H13, and reference it:

=NETWORKDAYS(B5, C5, $A$2:$A$5)

For a whole column of projects, copy the formula down with the holiday range locked. Two rules I enforce on every sheet:

1. Store holidays as real dates, not text. NETWORKDAYS tolerates text that looks like a date, but it is unreliable. Use actual date values or the DATE() function. A #VALUE! error almost always means a text imposter in the holidays range.
2. Weekend holidays are not double-counted. If Christmas falls on a Saturday and appears in your list, NETWORKDAYS does not subtract it twice. Safe to include observed-date duplicates only if your payroll policy actually observes them.

Where do you get the holiday list? A free public holidays CSV, like the one on this site, drops straight into the holidays column. Twenty-one countries, 2026 and 2027, no API key.

When weekends are not Saturday and Sunday: NETWORKDAYS.INTL

Middle Eastern workweeks, retail schedules, and shift operations need custom weekends:

=NETWORKDAYS.INTL(start_date, end_date, [weekend], [holidays])

The weekend argument is either a code or a 7-character string where 1 means non-working day, starting with Monday. "0000011" means the standard Saturday-Sunday weekend. "0000110" gives you Friday-Saturday weekends, the pattern used in several Gulf countries.

Three errors and what they mean

• Same start and end date, weekday, returns 1. Not 0. Both endpoints are inclusive. Same date on a Saturday returns 0.
• End date before start date returns a negative number. That is by design, and it is useful for overdue calculations.
• #NUM! from WORKDAY. The related WORKDAY function (which finds the date N working days out) throws #NUM! if the result lands on an invalid date or the weekend argument is malformed. Check the weekend code first.

The Google Sheets version

Identical syntax. =NETWORKDAYS(start, end, holidays) works in Sheets with the same inclusive-endpoint behavior, and NETWORKDAYS.INTL exists there too. Your holiday CSV imports as a date column the same way.

FAQs