Use '3D-Sums' with a couple of 'dummy worksheets.' Ex: insert two
worksheets, one with the name Last3Start and one with the name Last3End.
Position them before and after the most recent three months' sheets,
respectively. Then the totals would be =sum(Last3Start:Last3End!A1), for
instance, to add the values from A1 on those five sheets (the two dummies
which would have no data plus the three valid monthly worksheets).
All you do each month then is move those two dummy worksheets to the
appropriate positions in the workbook.


"sisko101" wrote:

Currently, I have a workbook with multiple worksheets. I am trying to
provide a return of the prior 3 months. Each month, when I add the next
month data, I have to update these formulas to refer to the data in the prior
two months worksheets i.e. this month I had to update last months formula
from pulling data from the Mar, Apr, & May worksheet to the Apr, May, and Jun
worksheets. How can I get a formula to automatically update and pull the
prior two months data to complete the return?