conditional formatting

[Guest]

I am entering a date to 2nd column of an array. The 1st column to the left
then picks-up this date and inserts the corresponding day of the week. This
is formatted using the "ddd" on custom cell formatting
e.g. B3 = 21/10/2004, A3 = B3 but the cells are formatted to represent the
date as a day of the week. "ddd" = Thu.
I want Conditional Formatting to identify every Sunday (Sun) and shade this
cell so that users can dessiminate each week. What do I do as Conditional
Formatting doesn't respond to this?

 

[JE McGimpsey]

One way:

CF: Formula Is =WEEKDAY(A3,1)=1