title: Python difference in datetime now against datetime now
body: <p>I have got into an issue or might quite possibly feature in turn! Not sure, wondering!! In python's datetime library, to get difference in time, as in below snippet.</p>
  
  <pre><code>&gt;&gt;&gt; import datetime
  &gt;&gt;&gt; datetime.datetime.now() - datetime.datetime.now()
  datetime.timedelta(-1, 86399, 999958)
  &gt;&gt;&gt; tnow = datetime.datetime.now()
  &gt;&gt;&gt; datetime.datetime.now() - tnow
  datetime.timedelta(0, 4, 327859)
  </code></pre>
  
  <p>I would like to understand why <code>datetime.datetime.now() - datetime.datetime.now()</code> is producing output as <strong>-1 days, 86399 seconds</strong> whereas assigning current time to some variable and computing difference gives desired output <strong>0 days, 4 seconds</strong>.</p>
  
  <p>The results seems to be bit confusing, it would be helpful if someone could decode whats going behind</p>
  
  <p>Note: I'm using Python 2.7</p>