One way:

Assume headings in row 1, then data in rows 2:xx, one row per day, date
in column A, numeric data in column B:

=SUM(OFFSET(B2,MAX(0, COUNTA(B:B)-31), 0, 30,1))




In article ,
CJ Barnes <CJ wrote:

I am trying to have a cell show me a sum for the past 30 days, updated daily.
The group of the 30 cells I'm summing will need to adjust down one cell
daily.