This is what I have so far

if ($dated =~ /^(?:[01]\d\/[0-3]\d\/(?:19|20)\d\d)?$/)
{
    my ($sec,$min,$hour) = qw( 0 0 12 );
    my ($mday, $mon, $year) = split /\//, $dated;
    $mon--; # because that's how unix/C treat the month value

    eval {
        my $dummy = timelocal($sec,$min,$hour,$mday,$mon,$year);
    };
    if (my $err = $@) {
        $passfail = 0;
        $errmsg = 'Unable to use date format. Please use "MM/DD/YYYY" 
+or MM-DD-YYYY for the Date Delivered Field';
        $errtitle = 'Validation Error';
        $seconds = 7;
    } else {
    };
}
else
{
    #User entered an invaild date.
    $passfail = 0;
    $errmsg = 'Unable to use date format. Please use "MM/DD/YYYY" or M
+M-DD-YYYY for the Date Delivered Field';
    $errtitle = 'Validation Error';
    $seconds = 7;
}

if ($dreceived =~ /^(?:[01]\d\/[0-3]\d\/(?:19|20)\d\d)?$/)
{
}
else
{
    #User entered an invaild date.
    $passfail = 0;
    $errmsg = 'Unable to use date format. Please use "MM/DD/YYYY" or M
+M-DD-YYYY on the Date Received field';
    $errtitle = 'Validation Error';
    $seconds = 7;
}
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But its still validating dates like: 15/10/2007