title: Strange behaviour when subclassing datetime.timedelta
body: <p>for convenience I want to create subclasses of datetime.timedelta. The idea is to define a class as such:</p>
  
  <pre><code>class Hours(datetime.timedelta):
      def __init__(self, hours):
          super(Hours, self).__init__(hours=hours)
  </code></pre>
  
  <p>so I can quickly create timedeltas like that:</p>
  
  <pre><code>x = Hours(n)
  </code></pre>
  
  <p>However, the code above produces a timedelta of n days instead of n hours. As an example, look at the following ipython session:</p>
  
  <pre><code>In [1]: import datetime
  
  In [2]: class Hours(datetime.timedelta):
     ...:     def __init__(self, hours):
     ...:         super(Hours, self).__init__(hours=hours)
     ...:         
  
  In [3]: print(Hours(10))
  Out[3]: 10 days, 0:00:00
  </code></pre>
  
  <p>I'm not able to explain this. Is anybody?</p>