Query Drupal User Table for: date created < $today - '100000'
You can achieve this using EntityFieldQuery as shown below:

$query = new EntityFieldQuery();
$query-&gt;entityCondition('entity_type', 'user')
  -&gt;propertyCondition('created', strtotime("-1 day"), '&lt;')
  -&gt;propertyCondition('uid', array(0,1), 'NOT IN');
$result = $query-&gt;execute();
if(!empty($result)){
    user_delete_multiple(array_keys($result['user']));
}