Use ISNA(A3) instead of A3="#N/A"

since #N/A represents 'value is not available' it can not be compared to
anything...

"Lost in Microbiology" wrote:

I have an expected due date in column A and an actual date in column B (if
there is no data a #N/A appears). I have a conditional format set to remind
me of upcoming, but am having trouble with one to tell me about past due.

A B
6/26/08 6/25/08
9/24/08 #N/A
3/20/08 3/25/08
11/18/08 #N/A

My first condition is: =AND(A3<TODAY()+30,A3=TODAY())

This one works fine, it highlights the cells of upcoming appointments.

My Second condition is: =AND(A3<TODAY(),A3="#N/A")

The second condition is not doing anything. I am missing something easy,
thanks for your help.