Customized columns sort

I added "Date Added" I managed to get the year, but I'd like to get the sort as "yr/mo/date".
Currently it is sorting as "mo/date/yr".

Enter something in the column definition property "Sort by", e.g.

I tried this:
But that made no change. What am I getting wrong?

You did not follow the rules for sets - have a look at the help on the regular expressions:

There is nothing called \y or \m

Thanks for the link. But my understanding of that is a bit above my pay grade, as it were.
A little hint?
Is it anything like this?
Where 4 represents the year, and 2 the month.


Or am I completely off?

Have you tried my suggestion?
the \d simply means "any digit" and the / (slash) is the separator between the digits.
As you have 3 parts in the date, the expression addresses these 3 parts which are then taken and put into a different order. The parts are numbered sequentially. And as there are no 4 parts, the $4 from your attempt addresses nothing.

not right either, but am I closer?
For my purposes, Sort could be: yr/mo. I don't need day unless the method does.

You talked about "dateadded" all the time. In fact you use the file creation date. Do you have any data in the field DATEADDED?
If not, replace that name in the expression with the real field oder property name.

And as this is a built-in date, you can use a sorting-friendly version of it:
Enter this name in "Sort by".

Screen Shot 2021-09-07 at 2.24.10 PM
thanks very, ohrenkino. That works.
I figured I was making more of it than it needed to be.