title: Quartz Cron Trigger, runs twice
body: <p>I have cron expression</p>
  
  <pre><code>0 0/45 * * * ?
  </code></pre>
  
  <p>Which happens to run twice, e.g. first run is 8:45 AM next run is 9:00 AM, 9:45 AM, ..10:00 AM</p>
  
  <p>Is something wrong?</p>