Here is another attempt with the Pivot Table.
I added a helper column in the main database to determine whether groupings of numbers based on your intended logic of date change overs....
you can change the header title as you desire...
in E2 enter a 1 to denote first group.
in E3 enter formula:
copied down.
Then in the pivot table, the source data would include this helper column in between the Account and Settlement Date columns.
You can hide this column in the Pivot table.
You can refresh the pivot table at will by right-clicking the table and selecting Refresh.
Bookmarks