node_submit changes $node->created if $node->date doesn't exist

I'm unsure if this is a bug or not in drupal 5.8, so I want to get your opinions on this.

I am opening a node, making some changes, and then saving it. My process is this:

$node = node_load($this_product_name_id);
// ...do some stuff here
$node = node_submit($node);
if ($node->validated) {
  node_save($node);
}

I noticed that the "created" field of my node table was being changed here. Looking into it, node_submit has this line, which is causing my grief:
$node->created = !empty($node->date) ? strtotime($node->date) : time();

I don't understand why, but it seems that it's checking for $node->date, which is never set by node_load. Maybe it should be?

I then saw that node_validate does set this properly, so maybe I should be using the $node = node_validate($node) function, but I am not. When I used it, it tried making me a new nid, which I didn't like.

Instead, I am now doing this:

$node = node_load($this_product_name_id);
// do some stuff here
$node->date = format_date($node->created, 'custom', 'Y-m-d H:i:s O');
$node = node_submit($node);
if ($node->validated) {
  node_save($node);
}

Is my process wrong (ie I need to find a way to incorporate node_validate() into my sequence? Or is this a bug with one of the functions that node->date should be set?

Either way, now I'm worked around, but I'd like to know what's best.

Thanks!!
berto