Manually set created date is overridden on contact save.

In RedhenContactEntityController::save() there is the following snippet:

      // New contact, set created prop.
      if (isset($contact->is_new) && $contact->is_new && !isset($contact->created)) {
        $contact->created = REQUEST_TIME;
      }
      // Set revision flags. By default, save a new revision and set it as
      // default.
      else {
        if (!isset($contact->is_new_revision)) {
          $contact->is_new_revision = TRUE;
        }
        if (!isset($contact->default_revision)) {
          $contact->default_revision = TRUE;
        }
      }

This means for new contacts $contact->created is always overridden regardless of it's current value. This means there is no straightforward way to set another created time ie. when importing contacts from another CRM system.

Proposed resolution

Add a check for an existing $contact->created and use REQUEST_TIME only as default.