Check input date format?

how to check input date format.
for example $input_date must be in format dd.mm.gg

script is execute like this:

bin/script1.sh 14.12.2009

script1.sh code:

#!/bin/sh

input_date=$1

CMD="/app/si/test/test.sh $input_date"
echo "*****"
$CMD

Try:

var="14.12.2009"
echo $var | grep -q  "[0-3][0-9]\.[01][0-9]\.[0-2][0-9][0-9][0-9]"
echo $?

date.sh

#!/bin/sh
echo $1 | awk -f date.awk

date.awk

BEGIN{
FS="."
}
{
 if ( $1 > 0 && $1 <= 31  &&  $2 > 0 && $2 <= 12 && $3 > 0 && length($3) == 4 ) {
 print "DATE FORMAT OK"
 }
 else{
 print "DATE FORMAT NOK"

 }
}

USAGE : date.sh StringDate