shell date

#!/bin/bash
#Program:
#    This program shows "Hello World!" in your screen.
#History:
#20150925 Susie First Release
PATH=/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
echo -e "I will use ‘touch‘ command to create 3files."
#echo "Please input your filename: "
read -p "Please input your filename: " fileuser
echo $fileuser

filename=${fileuser:-"filename1"}
#避免用户随意按enter，当fileuser为空时，filename=“filename1”；fileuser不为空时，filename=$fileuser

echo $filename
date1=$(date --date=‘2 days ago‘ +%Y%m%d)
date2=$(date --date=‘1 days ago‘ +%Y%m%d)
date3=$(date +%Y%m%d)

file1=${filename}${date1}
echo $file1
file2=${filename}${date2}
echo $file2
file3=${filename}${date3}
echo $file3
#touch "$file1"
#touch "$file2"
#touch "$file3"
#echo -e "Hello World!\a \n"
#exit 0