Continuously evolving Sum formula

Ian Groves

Is it possible to create a formula or workflow that would move/update our "90 Day total" column as new months come and go? I've attached what we are currently working with. The 90 Day Total is just a sum formula for each Jun Jul and Aug. The rest of the year is mapped in the exact same style, but for Sep Oct Nov and Dec. Once June passes, we want the 90 Day Total column to forget June, and move to July August and Sept instead of Jun July Aug, and so on as the year progresses.

Any help/advice is more than welcome!

Ian Groves

@Paul Newcome Sorry Paul, I saw your response to another question posed like this from about a year ago, but they had more criteria specified than I do and got lost in all the syntax. Would you be able to help with something like this?

Paul Newcome

Do you already have the columns for the other months in the sheet? Is there going to be year overlap, or did you want it to stop at December?

Ian Groves

Yes, the other columns are already in the sheet and we are going to stop at December

Paul Newcome

Ok. And which columns exactly are you wanting to add together? The hours or the dollar amounts?

Ian Groves

The dollar amounts

Paul Newcome

Let's give this a try 🤞...

=SUM(INDEX(Jan@row:Dec@row, 1, (MONTH(TODAY()) * 3) - 2), IFERROR(INDEX(Jan@row:Dec@row, 1, ((MONTH(TODAY()) * 3) - 2) + 3), 0), IFERROR(INDEX(Jan@row:Dec@row, 1, ((MONTH(TODAY()) * 3) - 2) + 6), 0))