title: Ceil a datetime to next quarter of an hour
body: <p>Let's imagine this <code>datetime</code></p>
  
  <pre><code>&gt;&gt;&gt; import datetime
  &gt;&gt;&gt; dt = datetime.datetime(2012, 10, 25, 17, 32, 16)
  </code></pre>
  
  <p>I'd like to ceil it to the next quarter of hour, in order to get</p>
  
  <pre><code>datetime.datetime(2012, 10, 25, 17, 45)
  </code></pre>
  
  <p>I imagine something like</p>
  
  <pre><code>&gt;&gt;&gt; quarter = datetime.timedelta(minutes=15)
  &gt;&gt;&gt; import math
  &gt;&gt;&gt; ceiled_dt = math.ceil(dt / quarter) * quarter
  </code></pre>
  
  <p>But of course, this does not work</p>