User Friendly Date Script

echo -n "Enter Date or leave blank for `date +%m/%d/%y`: " 
read mydat
echo -n "Enter Time or leave blank for `date +%H:%M`: " 
read mytime
if [ "$mydat" != "" ]
then
      mmdd=`echo $mydat | sed 's////g;s/..$//'`
      yr=`echo $mydat | sed 's////g;s/^....//'`
else
      mmdd=`date +%m%d`
      yr=`date +%y`
fi
if [ "$mytime" != "" ]
then
      newtime=`echo $mytime | sed 's/://g'`
else
      newtime=`date +%H%M`
fi
date "$mmdd$newtime$yr"