Backup directory under a pretty unique name

bkup

#!/usr/bin/env bash

now=$(date +"%Y%m%d_%H%M%S")

if [[ $1 == "" ]]
then
  echo "You need to specify the directory you need to backup: bkup PROJECT"
else

    dir="$1"
    backup="$dir"
    backup+="_"
    backup+="$now"

    cp -rvp $dir $backup

    if [ ${?} -eq 0 ]
    then
        echo "- Finished"
    else
        echo "- We had an issue"
    fi
fi