title: Find oldest/youngest datetime object in a list
body: <p>I've got a list of datetime objects, and I want to find the oldest or youngest one. Some of these dates might be in the future.</p>
  
  <pre><code>from datetime import datetime
  
  datetime_list = [
      datetime(2009, 10, 12, 10, 10),
      datetime(2010, 10, 12, 10, 10),
      datetime(2010, 10, 12, 10, 10),
      datetime(2011, 10, 12, 10, 10), #future
      datetime(2012, 10, 12, 10, 10), #future
  ]
  </code></pre>
  
  <p>What's the most optimal way to do so? I was thinking of comparing datetime.now() to each one of those.</p>