Without understanding what type of analysis / visualizations you want to do it is difficult to help you. I assume you have IDs for each of these events that are spread over several days. To best help you post examples of what you are trying to achieve.
Thank you Dean,
Unfortunately, I cannot share the data I am working with, but I will try to elaborate a bit.
The underlying data do not have IDs - if I had to guess, I would say that the primary key is (START_DT, START_TM) since that is guaranteed to be unique.
Let's call the time during which the event occurs "ON-TIME" and the rest of the time "OFF-TIME." I need to show the breakdown of ON-TIME and OFF-TIME as a percentage of time in a given period with granularity down to calendar days (I don't think I'll ever need to look at hours or minutes). So, I might have a viz that shows 10% ON-TIME and 90% OFF-TIME in 2012 and want to see that by month or by day.
Since the data are broken down by events rather than days, multi-day events pose a problem. If an event begins at 7:00PM on December 31st 2011 and ends at 2:00AM on January 1st 2012, I need the first 5 hours of that event to be aggregated in 12/31/11, 12/11, or 2011 while the last 2 hours of that event should be aggregated in 1/1/12, 1/12, or 2012. As it stands, I do not have a clean way of breaking down events into the days that they span.
Does that clarify the problem?