title: how to decode xml data into a human readable format
body: <p>I have some xml files which have been used as personal data files in an astrological application.</p>
  
  <p>The appliction does not exists more, but I still need the data. Opening the xml I have the following:</p>
  
  <pre><code>&lt;BirthDate&gt;2442260.7083333&lt;/BirthDate&gt;
  </code></pre>
  
  <p>or</p>
  
  <pre><code>&lt;BirthDate&gt;2436617.0375000&lt;/BirthDate&gt;
  </code></pre>
  
  <p>in this case real date is 17.02.1959. 12:54 (12:54 is the birthtime).</p>
  
  <p>or</p>
  
  <pre><code>&lt;BirthDate&gt;2446904.4652778&lt;/BirthDate&gt;
  </code></pre>
  
  <p>in this case real date is 18.04.1987. 23:10 (23:10 is the birthtime).</p>
  
  <p>Is there a way to decode this and get the date/time in a readable format?</p>