Shell script to classify pictures according to month taken

gistfile1.sh

#!/bin/bash

FILES=`find . -iregex '.*JPG'` 
for file in $FILES
do 
        lastmod=`exiftool $file | grep 'Create Date' | awk '{print $4}' | sed 's/:/-/g'| sort | uniq`
        echo "$file, Last Modification Date: $lastmod-"
        month=`date --date="$lastmod" "+%B%Y"`
        if [ ! -d $month ];then
                mkdir $month
        fi 
        cp $file $month
done