Use the FIND command to reduce old backup/files

A Bash script to remove/cleanup backups (or any files matching the date field in filename).
Uses FIND command - Example shown retains/saves 1st of month backup only if older than 90 days.

Create a shell script:
$ sudo nano /opt/scripts/

Edit for days desired (change +90 to your choice, and/or day of month '01', and/or filename) and save:

DS=`date "+%Y-%m-%d %H:%M:%S"`

### find >= 90 day - but leave/exclude a 1st day of month forever...
find "$FINDPATH"/backupname_* -name 'backupname_??-01-*' -prune -o -mtime +90 -exec ls {} \; >> "$LOG"

Set some permissions:
$ sudo chown root:root /opt/scripts/
$ sudo chmod 744 /opt/scripts/

Test run:
$ cd /opt/scripts/ && sudo ./

Running the above should produce a `ls` file list in your defined log.
The test above only lists files.
If the correct files are listed for deletion, just replace the find line with this (added 'rm'):
find "$FINDPATH"/backupname_* -name 'backupname_??-01-*' -prune -o -mtime +90 -exec ls {} \; -exec rm {} \; >> "$LOG"

Add to root crontab and you are done:
$ sudo crontab -e

Adjust to your liking and save:
## run on 2nd of month/each month:
0 0 2 * * /opt/scripts/