title: Spring cron expression for every after 30 minutes
body: <p>I have following Spring job to run after every 30 minutes. Please check my cron expression, is that correct?</p>
  <pre><code>0 0 0 * * 30
  </code></pre>
  <p>Here is a full cron job definition from the related Spring <em>configuration</em> file:</p>
  <pre class="lang-xml prettyprint-override"><code>&lt;bean id=&quot;autoWeblogPingTrigger&quot; class=&quot;org.springframework.scheduling.quartz.CronTriggerBean&quot;&gt;
      &lt;property name=&quot;jobDetail&quot; ref=&quot;jobDetailForWeblogPing&quot;/&gt;
      &lt;!-- run every 35 minutes --&gt;
      &lt;property name=&quot;cronExpression&quot; value=&quot;0 0 0 * * 30&quot; /&gt;
  &lt;/bean&gt;
  </code></pre>