files=( *.m2v )
for i in ${!files[@]}; do
    rand_date[i]=$(( $((RANDOM%37)) + 1970 ))$(printf "%02d" $((RANDOM%12 + 1)) )$(printf "%02d"  $((RANDOM%30 +1)) )
    touch -d ${rand_date[i]} ${files[i]}
done

IN_FILES=( $(ls -t -1 ${files[@]} )