This equation works as expected to sum values from row 3 based on their relationship to a series of dates listed in row 1:
=SUMIFS(I3:DV3, I$1:DV$1,">="&today()-86, I$1:DV$1,"<"&today())
I now have to prefix some of the row 3 input with asterisks '*', but as expected, this equation doesn't read those cells as numerical. For the purpose of this equation only, I need to strip the asterisks and read the numerical value(s).
Tried chatgpt (no help). I suppose I need to use SUBSTITUTE, but no idea how to incorporate it with this equation.
You may try:
=sum(ifna(filter(--substitute(I3:DV3,"*",),isbetween(I1:DV1,today()-86,today(),,0))))