title: xlrd retrieves wrong date when excel cell value is =TODAY()
body: <p>If the value in a cell is <code>=TODAY()</code>, xlrd wrongly retrieves the date of document's last save.</p>
  
  <p>Does anyone know where I can find the relevant code within <code>xlrd</code> sources so to edit? Any suggestions for a workaround will also be greatly appreciated.</p>