The formula I’ve been successfully using to determine the number of weekend days and public holidays of a project, is:
=M13-NETWORKDAYS(K13,L13,'2018 Public holidays'!$C$1:$C$11)
(M13 is the total number of days between K13, the start date and L13 the end date, '2018 Public holidays'!$C$1:$C$11...