Formula contains same data when i Save As a workbook with another
 

Pls reply,
I have workbook with multiple sheets, which i have to rename with every
month. In this workbook in a particular sheet where i have created a formula
which depends on other sheets. But when I Save it with another name and
deleted past months all numeric data but this formula taking
sum(sheet_cellno) from past months workbook.

Why this not changed automatically, Pls help me

Rao Ratan Singh