title: How to select a list of the latest times per day from a list of dates
body: <p>That question probably sounded extremely confusing, but it's difficult to describe what I want to do. Basically, I have a list of <code>DateTime</code> objects and I want to make a new list that contains the objects from the list that represent the latest time for each date represented in the list. For example, say I have a list containing these <code>DateTime</code>s:</p>
  
  <ul>
  <li>12/13/2012 2:00:00 AM</li>
  <li>12/13/2012 4:00:00 AM</li>
  <li>12/13/2012 8:00:00 PM</li>
  <li>12/14/2012 5:00:00 PM</li>
  <li>12/14/2012 3:00:00 AM</li>
  <li>12/15/2012 10:00:00 AM</li>
  </ul>
  
  <p>I want my results list to contain the following:</p>
  
  <ul>
  <li>12/13/2012 8:00:00 PM</li>
  <li>12/14/2012 5:00:00 PM</li>
  <li>12/15/2012 10:00:00 AM</li>
  </ul>
  
  <p>I know I can do this using LINQ. I'm just having a hard time trying to wrap my mind around what is happening. I think I have to select from an <code>IEnumerable&lt;IEnumerable&lt;DateTime&gt;&gt;</code> where the inner <code>IEnumerable</code> is a list of <code>DateTime</code>s that all have the same date, and then I want to order those by descending and select the first one.</p>
  
  <p>I am quite lost...</p>