Networkdays.intl

Hello. I would like to count how many "work" Fridays there in between two dates. I thought about use the NETWORKDAYS.INTL function and string value to determinate Friday as the only workday at the week: 1111011. But then I got an #NÚM. I guessed that's because the strings values could not lead to errors only if they match some of the given options of custom weekends of the formula (like "16 - only Fridays" as weekend; by the way the opposite of what I want). So I simulated the strings values for many of the options, like 0000010 that should be equal to "17 - only Saturday", but again I got an #NÚM. So I have no idea how to use string value input for the custom weekends on the NETWORKDAYS.INTL function.

Make sure you're entering that 1111011 as a TEXT STRING..with Quote marks
i.e.
"1111011"

I was entering the custom weekend through a cell reference: =DIATRABALHOTOTAL.INTL(B3;C3;A3;Feriados!$A$1:$A$54). So, at the cell A3 I put 1111011 without quote marks and thhen I got a #NÚM, inside the quote marks I got a #VALUE!. But using the apostrophe it worked, that's how I solved: '1111011. Inside the formula the correct way is use the quote marks like Jonmo1 said. Thanks everybody for all.

You're welcome.