Does anyone know how I can get a cell to show a sum of past 90 days of entries when I enter a date into another cell. Basically I would like when I enter yesterday's date in cell B3, it calculates from column L the previous 90 days where L days start in row 16. I have column B listing all the days of the year starting with Jan 1, 2007 through Dec 31, 2007. I am trying to keep up with employee days for any given past 3 months depending on what day I enter in cell B3.