Sub NetWorkDays()
Dim StartDate As Date
Dim EndDate As Date
Dim rng_holidays As Range
Dim WorkDays&
Dim arr()
Set rng_holidays = ActiveSheet.Range("C2:C5") 'setting the range of additional holidays which are within Mon-Fri
StartDate = Range("A2")
EndDate = Range("B2")
arr = rng_holidays
'As third parameter you ca use either range of additional holidays (dates) or array that include records of holidays
'WorkDays=Application.WorksheetFunction.NetworkDays(StartDate, EndDate, rng_holidays)
WorkDays = Application.WorksheetFunction.NetWorkDays(StartDate, EndDate, arr)
ActiveSheet.Range("D2") = rng_holidays
Set rng_holidays = Nothing
End Sub