title: How to retrieve date from table cell using PhpSpreadsheet?
body: <p>I have <code>xlsx</code> tables and I use PhpSpreadsheet to parse them. Some cells are formatted as date. The problem is that PhpSpreadsheet returns the values from date-formatted cells in an unspecified format:</p>
  <pre><code>// What it looks in excel: 2017.04.08 0:00
  $value = $worksheet-&gt;getCell('A1')-&gt;getValue();  // 42833 - doesn't look like a UNIX time
  </code></pre>
  <p>How to get the date from a cell in form of a UNIX time or a <code>DateTimeInterface</code> instance?</p>