function countdown(){
   date1=$((`date +%s` + $1));
   while [ "$date1" -ne `date +%s` ]; do
     echo -ne "$(date -u --date @$(($date1 - `date +%s`)) +%H:%M:%S)\r";
     sleep 0.1
   done
}
function stopwatch(){
  date1=`date +%s`;
   while true; do
    echo -ne "$(date -u --date @$((`date +%s` - $date1)) +%H:%M:%S)\r";
    sleep 0.1
   done
}