Conditional formatting: showing difference of 21 days or more

[Hexdax]

Conditional formatting does not work.
I'm trying to make it look like in picture (both are fine) but it does not work. What is wrong and how to make it work?

I need formatting when difference between dates is 21 days or over.

In the Book1.xlsx has a way I tried to do it; Conditional formatting rules manager and formula =ABS($A:$B)>=21

[AliGW]

Administrative Note:

We would very much like to help you with your query, however the thread title does not really convey what your request is about. Tell us what you are trying to do, not how you think it should be done.

Please take a moment to amend your thread title. Make sure that the title properly explains your request. Your title should be explicit and not be generic (this includes function names used without an indication of what you are trying to achieve).

Please see Forum Rule #1 about proper thread titles and adjust accordingly. To edit the thread title, open the original post to edit and then click on Go Advanced (bottom right) to access the area where you can edit your title.

(Note: this change is not optional. As yo are new here, I have done it for you this time.)

[Hexdax]

Sorry. I have edited the post and will continue to make a better posts in the future.

[AliGW]

It wasn't the post, it was the title, and I fixed it for you.

[HansDouwe]

Please try conditional rule

=($B1-$A1>=21)*COUNT($A1:$B1)=2

aplies to $A:$C

[AliGW]

CF rule for A2:

=AND($C2>=21,$C2<>"")

Applies to: =$A$2:$C$7

[Glenn Kennedy]

=AND($A2<>"",$B2<>"",$B2-$A2>=21)

as conditional formatting