title: How can I schedule task with celery which runs at the end of month?
body: <p>I need to set celery crontab to run at the end of month even different day as end of month(28~31).
  I know how to set crontab run at the end of month on shell command like this:</p>
  
  <pre><code>55　23　28-31 * * /usr/bin/test $( date -d '+1 day' +%d ) -eq 1 &amp;&amp; exec something
  </code></pre>
  
  <p>But on celery schedule I don't know how to do this setting. 
  Is there any way to schedule task which runs at the end of month on celery?<br>
  It seems only way is to override <code>is_due</code> method on <code>celery.schedules.crontab</code>.</p>