tmparisi on "Further Date Validation"

This is what was added to the post-functions.php file right above line 1367 ($form_unique_ip = $row['form_unique_ip'];).... thanks to MachForm it now works perfect:

if ($form_id == 2) {
//date validation
$date_element_id = 3;

if (!empty($table_data['element_' . $date_element_id])) {
if (date("D",strtotime($table_data['element_' . $date_element_id])) == 'Mon') {
$error_elements[$date_element_id] = 'You unable to select Moday';
}

}
}