Adjusting formula to calculate weekdays only

That worked perfectly.
Now I have to do the same for formulas where multiple dates are considered. (Below...)
Formula 1
=IF(B5<1,"",IF(H5<1,"PENDING",IF(P5>0,(P5-N5)+(M5-K5)+(J5-H5),"PENDING")))

Formula 2
=IF(B5<1,"",IF(M5<1,"PENDING",IF(N5>0,N5-M5,"PENDING")))

B5=Job Number
H5=Date Submitted to Dept. #1
J5=Date Received by Dept. #2
K5=Date Completed by Dept. #2
M5=Date Received by Dept. #3
N5=Date Completed by Dept. #3
P5=Date Completed by Dept. #1

I keep getting too few arguments