title: Pandas timestamp on array
body: <p>Pandas does not convert my array into an array of Timestamps:</p>
  
  <pre><code>a = np.array([1457392827660434006, 1457392828660434012,  1457392829660434023,1457474706167386148])
  pd.Timestamp(a)
  </code></pre>
  
  <p>gives an an error :</p>
  
  <pre><code>TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-42-cdf0e494942d&gt; in &lt;module&gt;()
        1 a = np.array([1457392827660434006, 1457392828660434012, 1457392829660434023,1457474706167386148])
  ----&gt; 2 pd.Timestamp(a)
  
  pandas/tslib.pyx in pandas.tslib.Timestamp.__new__ (pandas/tslib.c:8967)()
  
  pandas/tslib.pyx in pandas.tslib.convert_to_tsobject (pandas/tslib.c:23508)()
  
  TypeError: Cannot convert input to Timestamp
  </code></pre>
  
  <p>Whereas looping on the array elements works just fine :</p>
  
  <pre><code>for i in range(4):
      t = pd.Timestamp(a[i])
      print t
  </code></pre>
  
  <p>gives :</p>
  
  <pre><code>2016-03-07 23:20:27.660434006
  2016-03-07 23:20:28.660434012
  2016-03-07 23:20:29.660434023
  2016-03-08 22:05:06.167386148
  </code></pre>
  
  <p>As expected.</p>
  
  <p>Moreover when that array is my first column in a csv file, it does not get parsed to a TimeStamp automatically, even if I specify parse_date correctly.</p>
  
  <p>Any help please?</p>