Re: Sum row of numbers based on date range for columns
For those discovering this themselves ....
To get this so that it worked when copied down to addition rows I modified the formula as follows:
=SUM(OFFSET(INDEX($I$21:$AM$21,1,MATCH(DAY($AJ$1),$I$21:$AM$21,0)):INDEX($I$21:$AM$21,1,MATCH(DAY($AJ$2),$I$21:$AM$21,0)),ROW(A1),0))
This then uses absolute references for the dates and header rows, but a relative reference for the source row to be SUMed.
Thanks again for this bit of awesome advice.