Site events for index widget

I am currently looking into enabling the event calender widget on the index page available through the "widget manager" plugin.

Adding it is easy (add "index" in start.php widget registration), but it seem the current widgets only show group/personal events and not the site events which I would like to show on the index page. Thus the widget on the index page remains empty if added.

It seems to me (not very good at php) from looking at the code, that the site calendar items are actually handled a bit different from the group and personal calender items. Thus I am having difficulties determining how to make the index widget work.

Is there a function to get all the site calender items that I am overlooking?