The first task is to create a formula that can detect the number of the day
of your sheet.
=RIGHT(CELL("filename",A1),1)
and the corresponding sheet to subtract will then be
=RIGHT(CELL("filename",A1),1)-1

To use this information in a formula, we can use the INDIRECT function,
which combines text and formulas to create references. Assuming you are
dealing with cell A2 in each respective worksheet:

=A2-INDIRECT("'Day "&RIGHT(CELL("filename",A1),1)-1&"'!A2")

Placing this formula in sheet Day 3 would create a formula equivalent to:
='Day 3'!A2 - 'Day 2'!A2

Notes:
Do NOT change "filename" to your actual file name. This is part of the
formula structure.
Pay close attention to the placement of double and single quotes within the
INDIRECT function.
Within the CELL function, it does not matter what cell you reference.

--
Best Regards,

Luke M
*Remember to click "yes" if this post helped you!*


"KellyLC" wrote:

Is it possible to automatically change a specific formula which references
the previous worksheet? example:
Day 1 is subtracted from the Day 2 total, when I copy the sheet to name it
Day 3, I want the formula to subtract Day 2 from Day 3. I have to make 31
copies for each day of the month. Is there an easier way to make the change