title: How to check if date is a monday (PHP)
body: <p>how can I check if my date is a monday ?</p>
  
  <p>Thats the date I want to check: 2020-04-20 00:00:00</p>
  
  <p>I tried this, but it doesn't work:</p>
  
  <pre><code>if(date('D', $datum) === "Mon")
  {
    echo "yes!";
  }
  </code></pre>
  
  <p>Can someone please help me there, or show me an other way to check it ?</p>