Hi -
Currently, there isn't an easy way to do this without either: [1] modify the widget plugin or [2] create your own customized theme template.
I think the first option will probably be easier -- if you go into your event-calendar plugin folder and open the file widget.php and go to around line 108 you should see code that says:
echo $before_widget . $before_title;
echo ec3_default_string($options['title'],'Upcoming Events');
echo $after_title;
ec3_get_events($options['limit']);
echo $after_widget;
Change it to:
echo $before_widget . $before_title;
echo ec3_default_string($options['title'],'Upcoming Events');
echo $after_title;
ec3_get_events($options['limit'],'%DATE%: <a href="%LINK%">%TITLE%</a> (%TIME%)','','m/j');
echo $after_widget;
You can read more about customizing the ec3_get_events() function at: http://wpcal.firetree.net/template-functions/ec3_get_events/
We should add that to the widget plugin -- is nice functionality.
Damon