Linux script to rotate backup files (keeps past 7 days then switches to weekly for the past 30 days then keeps only monthly files)

clean-daily-backups.sh

#!/bin/bash

# backup location with daily files
# format: .*_[DATE]_.*
# date format: YYYY-MM-DD
backupLocation="/path/to/backups"

if [ -z "$backupLocation" ]; then
    echo 'Must set $backupLocation'
    exit 1
fi

# delete non Sunday and non "first day of the month" files older than a week
find $backupLocation -mtime +7 | while read fname; do
    fileDate=`echo $fname | awk -F"_" '{print $2}'`
    fileDow=`date --date="${fileDate}" "+%a"`
    fileDom=`echo $fname | awk -F"_" '{print $2}' | awk -F"-" '{print $3}'`
    #echo "${fname} - ${fileDow} - ${fileDom}"
    if [ "${fileDow}" != "Sun" ] && [ "${fileDom}" != "01" ] && [ -f ${fname} ]; then
        #echo "rm ${fname} (${fileDow} - ${fileDom})"
        rm ${fname}
    fi
done

# delete non first day of month files older than a month (clear out weekly files)
find $backupLocation -mtime +30 | while read fname; do
    fileDom=`echo $fname | awk -F"_" '{print $2}' | awk -F"-" '{print $3}'`
    #echo "${fname} - ${fileDom}"
    if [ "${fileDom}" != "01" ] && [ -f ${fname} ]; then
        #echo "rm ${fname} (${fileDom})"
        rm ${fname}
    fi
done