Fix NETWORKDAYS / NETWORKDAYS.INTL #NUM! in Google Sheets (bad dates or weekend number)

Updated 2026-09-29

NETWORKDAYS counts working days between two dates, skipping Saturday/Sunday and an optional holiday list. NETWORKDAYS.INTL does the same with a custom weekend. #NUM! means a date serial, a holiday serial, or the weekend code is outside what those functions will accept. The formula parsed. The count cannot run.

This page is NETWORKDAYS / NETWORKDAYS.INTL #NUM!. It is not WORKDAY #NUM! (WORKDAY returns a date, not a count). It is not out of domain (SQRT(-1), LN(0), FACT(171)). Keep the Google Sheets UI in English.

Recreate it on a blank sheet

Open a blank spreadsheet. In A1 type kickoff. In A2 enter =DATE(2024,6,3) (a Monday). B1 ship. In B2 enter =DATE(2024,6,14) (a Friday). C1 holiday.

A count the function can return. In E1 type net_ok. In E2 enter =NETWORKDAYS(A2,B2). The cell shows 10 (weekdays from 3 Jun through 14 Jun, no holidays). That row is the control: two real dates, default weekend, a number.

E2 selected. Formula bar shows =NETWORKDAYS(A2,B2). E2 is 10 with no error triangle. A2 is 6/3/2024. B2 is 6/14/2024.

Invalid weekend code on NETWORKDAYS.INTL. In E4 type weekend_99. In E5 enter =NETWORKDAYS.INTL(A2,B2,99). The cell shows #NUM!. Weekend must be 1–7, 11–17, or a seven-character 0/1 string (Monday-first). 99 is none of those. Leave E5 broken.

E5 selected. Formula bar shows =NETWORKDAYS.INTL(A2,B2,99). E5 is #NUM!. Tooltip: Function NETWORKDAYS.INTL parameter 3 value is 99. Valid values are between 1 and 7, or 11 and 17 inclusive. E2 is still 10.

Holiday list with an impossible serial. In C2 enter =DATE(2024,6,12). In C3 type 4000000 as a number — not a date this calendar can use. In E7 type bad_holiday. In E8 enter =NETWORKDAYS(A2,B2,C2:C3). The cell shows #NUM!. C2 is a fine holiday. C3 is not. Leave E8 broken.

End date overflow. In E11 enter =NETWORKDAYS(A2,4000000). #NUM! — B-side is not a date Sheets will count to. Leave E11 broken.

Text dates are a different error. =NETWORKDAYS("kickoff",B2) is #VALUE!, not #NUM!. That is wrong type / DATEVALUE locale. Stay on E5 and E8 for this page.

WORKDAY contrast. In G5 enter =WORKDAY.INTL(A2,10,99). Also #NUM!, also weekend 99, but the function is WORKDAY.INTL and the result you wanted is a date. That primer is WORKDAY #NUM!. Leave G5 as the contrast. Do not copy a WORKDAY day-count fix onto E5.

Leave E5, E8, and E11 as the broken formulas. Leave E2 as 10.

What is actually wrong

NETWORKDAYS.INTL’s third argument is a weekend code, not “how many weekend days.” 1 is Saturday+Sunday (the NETWORKDAYS default). 7 is Friday+Saturday. 11 is Sunday only. 99 is not on the list. #NUM!.
A seven-character weekend string must be seven 0/1 characters, Monday first (0000011 is Saturday+Sunday). "weekend" and "11111111" are invalid. Sheets may show #NUM! or #VALUE! depending on the string. Treat both as a bad weekend argument.
Holidays must be valid date serials. A leftover 4000000, a negative serial Sheets will not use, or a value that is not a date in this file’s range, makes NETWORKDAYS #NUM!. One bad cell in C2:C3 poisons the call even when C2 is fine.
An end (or start) serial the calendar cannot represent is the same #NUM!. That is overflow in the date system, not FACT(171) — but it shares the error value with out of domain.

This is not WORKDAY / WORKDAY.INTL. Those answer “what date is N workdays after kickoff?” See WORKDAY #NUM!. E5 parsed NETWORKDAYS.INTL. The result type you wanted is a count sitting in E2.

This is not SQRT(-1). See out of domain. E5 is a weekend code, not a negative square root.

This is not #VALUE! from "kickoff" or locale-shaped date text. Parse starts with DATE / DATEVALUE first. See DATEVALUE locale.

This is not #N/A. Nothing is being looked up. See what #N/A means.

Fix

Leave E5, E8, and E11 broken so #NUM! stays on the sheet.

Pass a real weekend code. In F5 enter =NETWORKDAYS.INTL(A2,B2,1). The cell matches E2 (10). For Friday+Saturday, pass 7, or the string 0000110. Do not invent 99.

F5 selected. Formula bar shows =NETWORKDAYS.INTL(A2,B2,1). F5 is 10 with no error triangle. E5 is still #NUM!. E2 is 10.

Clean the holiday list. Keep only real dates. In F8 enter =NETWORKDAYS(A2,B2,C2). The cell is 9 if 12 Jun is skipped as a holiday inside the window. Do not point holidays at a mixed column that still holds TBD or a huge number. Helper: =IF(ISNUMBER(C3)* (C3>0),C3,"") and use a range of true dates only.

Keep both ends as DATE. =DATE(2024,6,3) and =DATE(2024,6,14), not locale-fragile "6/3/2024" if you can avoid it.

Do not wrap E5 in IFERROR. You still have no working-day count. See IFERROR vs IFNA. IFNA will not catch #NUM!.

If NETWORKDAYS / NETWORKDAYS.INTL is #NUM!, read the weekend argument, then ISNUMBER on every holiday, then whether start and end are real dates. A text start is #VALUE!. A WORKDAY formula is the other primer.

NETWORKDAYS vs WORKDAY (and start after end)

NETWORKDAYS answers “how many workdays sit between these two dates?” The result is a count. E2 is 10.

WORKDAY answers “what date is 10 workdays after kickoff?” The result is a date. Swapping them looks plausible in English and returns the wrong type of answer. #NUM! on WORKDAY is WORKDAY #NUM!. This page stays on the count.

Weekend 99 is the same illegal code on both families. Fix the code (1–7, 11–17, or seven 0/1 characters). Do not pass 2 because “the weekend is two days” unless you meant weekend code 2 (Sunday+Monday).

Start after end is not #NUM!. In F11 enter =NETWORKDAYS(B2,A2). The cell is -10 (or a negative count), not an error. Sheets will count backwards. If you expected #NUM! and got a negative, swap the arguments or wrap ABS only if a reversed pair should still print a positive length. Do not treat that negative as overflow. Overflow and weekend 99 are the red triangles on E5 and E11.