I have a series of values in columns, one for each day of the month, but as the month progresses, the forecast values are replaced by actual values. What is the best way to make the sheet add only the actual values by reading a cell giving the last actual date? thanks in advance.

Don't think I comprehend the full concept of your desires. Personally I would maintain both forecast and actual values on my spreadsheet by separating the columns. Can you reword/redefine your desired results? Also, are all the values input maually or otherwise? Bryan

In my opinion, you should have separate fields for estimated values and actual values. You could then have a third row of fields that uses an if statement to use the actual value if it exists otherwise it uses the estimated value. Then use the sum of this third row. Michael J

I used separate rows for actual and forecast data with the if statement to ascertain that the actual field was blank. Since I was trying to save space and didn't want to use the extra rows, I just hide the rows containing the actual and the forecast, leaving only the conditional result. The user of the information is very big on the actual + forecast summation. Thanks to both of you. James Young