title: Timestamp to date in Logstash
body: <p>I am trying to convert a string field called timestamp with value 1510722000000 in date format field in Logstash. My sole purpose is to visualize data in kibana using this date field. I tried using the date filter but it does not create the target field for me. Can anyone tell me How can I achieve this</p>
  
  <p>My date filter looks like this </p>
  
  <pre><code>date {
      timezone =&gt; "UTC"
      match =&gt; ["timestamp", "UNIX_MS"]
      target =&gt; "@timestamp1"
  }
  </code></pre>