Date Validation

Shell Programming and Scripting
1

the user have to input the date format in mmddmmhhyyyy (month,date,minutes,hour,year)
i want a shell script to check whether the user has properly input in the above said manner.
kindly advice

2 
read date
if [ ${#date} -lt 12 ]
then
  echo Not enough information
elif [ ${#date} -gt 12 ]
then
  echo Too much information
else
  case $date in
    *[!0-9]*) echo Invalid character entered ;;
    *) echo Thank you ;;
  esac
fi

Then you should check that the values for each component are within a valid range.

3

If have GNU date you can use date to check it, but the input must be in an accepted format of date (see: man date), maybe you can ask the user to input the date directly in the good format. It will check if it's really a valid date.

until date -d $DATE
do read -p "Enter date: " DATE
done