sumif based on dates

*** Many thanks!!!


I'm stuck on this formula and it's not returning the right values.

So this is the structure of what I'm trying to do, I'm looking at EBITDA tab in row 5 which has dates going across, followed by C3 which is a date, and ending with $ amounts in row 7. I'm trying to sum everything in row 7 within the first 12 months of C3. However, when I sum up the first 12 months, it's not return the same value as I am calculating on my calculator.

This is the formula I have right now:
SUMIF(EBITDA!$B$5:$CG$5,EOMONTH(C3,12),EBITDA!$B7:$CG7)

I tried this formula as well, but it's not the same as well:
SUMIF(EBITDA!$B$5:$CG$5,"<EOMONTH(C3,12)",EBITDA!$B7:$CG7)

Thanks for the help!