title: Solr extract substring from query
body: <p>I am new to <strong>Solr</strong> and I have had a difficult time with the following issue: </p>
  
  <p>I am trying to extract from the following field, in the web interface, just the hour:</p>
  
  <pre><code>  "2016-08-15T10:28:03Z"
  </code></pre>
  
  <p>Is there a function, like in SQL, to extract the substring given a pattern?</p>