title: Slack reminder for every three months
body: <p>I am trying to set a Slack reminder for every three months:</p>
  
  <pre><code>/remind #random "yada yada https://www.gebruikercentraal.nl/events.ics." every 3 months
  </code></pre>
  
  <p>but this doesn't work. This does work instead:</p>
  
  <ul>
  <li>every month</li>
  <li>every 2 weeks</li>
  </ul>
  
  <p>Any ideas what I am doing wrong? </p>