how to count results in a Calendar view? I enable the calendar module, then "Add view from template" on /admin/structure/views/add-template, but I cannot count nodes published at the same day in the month view by following this tutorial.
I want events occurred in the same day can be counted like "3 events occurred" other than the original output in the red box, and the counted field can be rewritten. 


I tried aggregation feature of views, but no luck.
Finally, I get it working.
After I turn on View's setting "Show the SQL query", I notice there is an unnecessary GROUP BY field "nid" in the Calendar view, then I unset this field in a hook_query_alter(QueryAlterableInterface $query) as below:

if ($query-&gt;hasTag('views_' . $view_name)) {
    $fields =&amp; $query-&gt;getGroupBy();
    unset($fields['nid']);
}