Required date error message(s)

Since nobody hasn't noticed this yet/doesn't know a solution, here's a quick fix I'm currently using to get rid of these spammy error messages. It's dirty, but it works.

In a custom module, create a new validate function for your form:

function mymodule_form_alter(&$form, $form_state, $form_id) {
     if($form_id = 'my_content_type_node_form') {
          $form['#validate'] = array('my_custom_validation');
     }
}

Then, in your new custom validation function:

function my_custom_validation() {
     
     // Retrieve all current form messages
     $errors = form_get_errors();

     // Unset these for each specific date field you might have
     unset($errors['field_mydate][0][value][day']);
     unset($errors['field_mydate][0][value][month']);
     unset($errors['field_mydate][0][value][year']);

     // Clear all current messages
     drupal_get_messages('error');
     
     // Loop through each error and add them back to the Drupal form error system
     // Notice that, in order to get the field names right, some additional processing is done (str_replace)
     foreach($errors as $key => $error) {
          form_set_error(str_replace(str_replace('][0][value', '[0][value]', $key), $error);
     }

}

Hope some more experienced developers could come up with a cleaner way to solve this though. This solution removes the 3 required messages, but keeps the generic message: "Field MyDate has errors. The year must be a number between 1 and 4000. The day must be a number between 1 and 31."