A formula that doesn't work until left blank

[kmilogon]

Hello All:

I need help. It seems preety simple but haven't been able to find it in another thread.

I have a cell containing a date.
By default, the first time the book is open this date should be =today()
The problem comes when:
If this cell is modified the new value previls.
if this new value is erased the =today() should get stablished back.
If the book gets open the next day, the original date (modified or not ) should prevail.

Any clue?
Thanks for everything,
KM

 

[Andrew Poulsom]

Welcome to MrExcel.

You would need macros to do that.