title: pandas df.apply TypeError data type not understood
body: <p>I'm trying to apply an operation to every value in a datetime series. I've reduced this to a lambda print to illustrate the problem.
  This works in another similar dataframe but not on this one? Python is version 3.5.1, pandas version 0.17.1. </p>
  
  <p>Some more padding to satisfy the SO question verbosity requirement.</p>
  
  <pre><code>print(dfY.info())
  print(dfY)
  dfY.apply(lambda rr: print(rr['predicted_time']), 1)
  </code></pre>
  
  <p>output</p>
  
  <pre><code>&lt;class 'pandas.core.frame.DataFrame'&gt;
  Int64Index: 21 entries, 0 to 20
  Data columns (total 1 columns):
  predicted_time    21 non-null datetime64[ns, pytz.FixedOffset(60)]
  dtypes: datetime64[ns, pytz.FixedOffset(60)](1)
  memory usage: 336.0 bytes
  None
                predicted_time
  0  2005-02-01 02:40:00+01:00
  1  2005-02-01 02:40:00+01:00
  2  2005-02-01 02:40:00+01:00
  3  2005-02-01 02:40:00+01:00
  4  2005-02-01 02:43:00+01:00
  5  2005-02-01 02:43:00+01:00
  6  2005-02-01 02:43:00+01:00
  &lt;snip&gt;
  19 2005-02-01 02:50:00+01:00
  20 2005-02-01 02:50:00+01:00
  
  ---------------------------------------------------------------------------
  TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-43-8ae0cf570812&gt; in &lt;module&gt;()
        1 print(dfY.info())
        2 print(dfY)
  ----&gt; 3 dfY.apply(lambda rr: print(rr['predicted_time']), 1)
  
  /.../Projects/Software/TimeTillComplete/venv/lib/python3.5/site-packages/pandas/core/frame.py in apply(self, func, axis, broadcast, raw, reduce, args, **kwds)
     3970                     if reduce is None:
     3971                         reduce = True
  -&gt; 3972                     return self._apply_standard(f, axis, reduce=reduce)
     3973             else:
     3974                 return self._apply_broadcast(f, axis)
  
  /.../Projects/Software/TimeTillComplete/venv/lib/python3.5/site-packages/pandas/core/frame.py in _apply_standard(self, func, axis, ignore_failures, reduce)
     4017             # Create a dummy Series from an empty array
     4018             index = self._get_axis(axis)
  -&gt; 4019             empty_arr = np.empty(len(index), dtype=values.dtype)
     4020             dummy = Series(empty_arr, index=self._get_axis(axis),
     4021                            dtype=values.dtype)
  
  TypeError: data type not understood
  </code></pre>