title: Java quartz scheduler: convert unix cron format to quartz cron format
body: <p>I want to check if given DateTime matches unix cron format or not. I was trying to use Quartz, but Quartz doesn't support "Day of Month" and "Day of Week" are both "*". </p>
  
  <p>For example: </p>
  
  <pre><code>0 * * * * * (which means run every minutes) is not supported in Quartz
  </code></pre>
  
  <p>because it must be </p>
  
  <pre><code>0 * * * * ? or 0 * * ? * *. 
  </code></pre>
  
  <p>Can someone tell me why and also tell me how can I match a given DateTime to Unix cron format?</p>
  
  <p>Thanks</p>