protected function updatePublishedAt(Eloquent $content)
    {
        $start = new Carbon('0000-00-00 00:00:00');

        if ($content->getAttribute('status') !== Eloquent::STATUS_PUBLISH) {
            return false;
        }

        $published = $content->getAttribute('published_at');

        switch (true) {
            case is_null($published):
                # next;
            case $published->format('Y-m-d H:i:s') === '0000-00-00 00:00:00':
                # next;
            case $published->toDateTimeString() === $start->toDateTimeString():
                return true;
            default:
                return false;
        }
    }