Offset formula not working together with if

Hi,

In the file attached I'm not able to make Offset work properly together with the if statement.
The idea is to have a dynamic range based on the month, if that month contains half day of working it needs to add 0,5
After analyzing the issue seems to be in the offset part more exactly in the OFFSET width part, where if statement has been applied

anhy help solving the #value issue is more then welcome, been breaking my had on this one for some time

Giving numbers and an expected result would be helpful in getting a solution

why do you use offset?
it is better to use a sorted table and lookup
=SUMPRODUCT(LOOKUP($F3:$N3,$B$2:$C$8))

btw, wb looks very familiar

1. Because of if it is array formula and must be finished by Ctrl+Sift+Enter
2. However Offset is volatile and better to replace OFFSET($A6;0;31*(SelectedMonth-1)+3;1;31) by INDEX(5:5;31*(SelectedMonth-1)+3):INDEX(5:5;31*(SelectedMonth)+3)
3 For whole year =SUMPRODUCT((D5:NK5<>"")/((D5:NK5=$NZ$13)+(D5:NK5=$NZ$14)+1)*($D$1:$NK$1))

Thanks BMV working great now