I'm trying to write a formula to summarize warranty dollars for "treaters" in December to present on a dashboard. Below is what I have for a formula but it is saying "#invalid operation" and I haven't been able to figure out what I'm doing wrong.
=SUMIFS(Treater:Treater, Year:Year, IF(Month:Month = 1, =(YEAR(TODAY()) - 1), =YEAR(TODAY())), Month:Month, =(MONTH(TODAY()) - 1))
Here's what I was using that worked until we crossed into the new year: =SUMIFS(Treater:Treater, Year:Year, =YEAR(TODAY()), (Month:Month), =(MONTH(TODAY()) - 1))
Any suggestions would be greatly appreciated! Thanks!