Why does ADRCI not purge listener trace files

Hello

For disk space management on oracle database binary filesystem, I use bash script to purge log files using adrci commands.

My question is why does adrci not purges/deletes older listener trace log files?

I am using log age at 8 days, and yet I continue to see files as old as July 15 in the following example:

-bash-4.2$ pwd

/u01/app/oracle/diag/tnslsnr/scv-bdmsctlg-stage-ora02a/listener

-bash-4.2$ ls -lt

total 5157208

-rw-r----- 1 segoracle segoinstall 3005368877 Jan 11 15:59 listener.log

-rw-r----- 1 segoracle segoinstall 190322028 Sep 24 13:39 listener_12.log

-rw-r----- 1 segoracle segoinstall 190102372 Sep 17 13:19 listener_11.log

-rw-r----- 1 segoracle segoinstall 189850526 Sep 10 15:44 listener_10.log

-rw-r----- 1 segoracle segoinstall 189953753 Sep 3 12:08 listener_9.log