incorrect variable name in hook_views_data_alter()

function date_views_views_data_alter(&$data) {
  // Mark all the core date handlers as date fields.
  // This will identify all handlers that directly use the _date handlers,
  // will not pick up any that extend those handlers.
  foreach ($data as $module => &$table) {

The views data array is not keyed by module, but by tablename.