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.