title: Pandas read excel with mixed date formats
body: <p>I am trying to read Excel that has date values in one column. They are however in 2 different formats:</p>
  
  <pre><code>03.07.2017
  03.07.2017
  30/06/2017
  30/06/2017
  30/06/2017
  03.07.2017
  03.07.2017
  </code></pre>
  
  <p>07 and 06 are month numbers.</p>
  
  <p>I import excel with:</p>
  
  <pre><code>denik=pd.read_excel('obchodnidenik.xlsx',converters={'Vstup - datum':str})
  </code></pre>
  
  <p>However the dates are converted differently.</p>
  
  <p>I get two date formats that have switched dates/months:</p>
  
  <pre><code>'30/06/2017'
  '2017-03-07 00:00:00'
  </code></pre>
  
  <p>What is the best way to convert all values into correct datetime?</p>