Here's what i'm trying to do:
I have a spreadsheet that has columns for "referral date", "intake
consultation date", "monitoring date", "group date" and "1:1 date". At the
end of my spreadsheet, i have a section that calculated the difference (in
days) between each of these dates. Each row will have "referral date" and
"intake consultation date". But for each row, there may be a date in either
just one, a combination of two, or all three of "monitoring date", "group
date" and "1:1 date".

The problem is that in situations where there is a "referral date" and
nothing in the "monitoring date" column, the formula is giving me a negative
number. I'm not sure why it would give me a number at all, let alone a
negative one. Does anyone know why it's doing this? Or how to fix it?

Thanks.