=NETWORKDAYS(N9,M9,$S$10:$S$17)

This is my formula, I'm trying to get the number of days between 2 dates,
not including weekends or hilidays. N9 and M9 are the dates, and $S$10:$S$17
is my list of holiday dates I do not want included. I can't figure out why
the formulat isn't working for me. I have dates in each cell.

Thanks in advance.