Customizing what is displayed on a date in the Calendar template view

I have multi-day events, which I know are not supported by the current Events app. That said, I've added the ability to enter two dates on each event and would like to be able to display them both on the Calendar view. I can't for the life of me figure out what template controls what is shown on a specific day on the sample calendar.html template.

It looks as though it is event_day.html that is displayed on each date. Is there any way to change it so that a different template is used for the day display?

Waiting, semi-patiently, for the long anticipated event app update.