Hello.
I appreciate help on this topic. I'm very new to excel's conditional
formatting capabilities and I need help on the following:

I have a worksheet where I am using columns A and B to be fashioned
into a type of "reverse" library checkout card; I want to flag when 120
days have passed since an item has been checked out. All cells are
blank with the exception of the formatting applied to cells in column
A. For example, Condition 1 on cell A1 has the formula:

=IF(ISBLANK(B1),(A1-TODAY())<120)

**I've also tried =IF(ISBLANK($B1),($A1-TODAY())<120)

My objective is to turn any cell in column A green with white text when
any date entered is over 120 days overdue; there are no fixed dates
already entered. Dates are entered in on column A as the item is
checked in.

My formula works to some extent. The problem I'm experiencing is that
the column A cells turn green before ANY date is entered. The
condition is tested before the date is entered. When the date is
entered, the text turns white, as expected. Once I type the check-out
date in cell B1, it turns cell A1 back to normal text/background; that
part works fine.

I've searched this forum for clues. A couple of postings are close to
what I want and I've tested. But they are working with values already
in the cells.