Hi ,
If I state your conditions in plain English , what you want is that the cell should turn GREEN under the following conditions :
1. If rDate is blank or
2. If rDate is between nDate and ( nDate + nDays )
The only way this can be tested for is by an OR condition , as follows :
=OR(rDate="",AND(rDate>=nDate,rDate<=(nDate + nDays)))
For the RED condition , you can just put a NOT outside the above formula , as in :
=NOT(OR(rDate="",AND(rDate>=nDate,rDate<=(nDate + nDays))))
or you can simplify this to :
=AND(rDate<>"",OR(rDate<nDate,rDate>(nDate + nDays)))
Narayan