title: How do I get missing day of array?
body: <p>I have an array with dates from today -> today + 14 days.
  Structure like this:</p>
  
  <pre><code>Array
  (
      [0] =&gt; Array
          (
              [0] =&gt; Array
                  (
                      [datum] =&gt; DateTimeImmutable Object
                          (
                              [date] =&gt; 2019-11-04 16:30:00.000000
                              [timezone_type] =&gt; 1
                              [timezone] =&gt; +01:00
                          )
                  )
  
          )
  
      [1] =&gt; Array
          (
              [0] =&gt; Array
                  (
                      [datum] =&gt; DateTimeImmutable Object
                          (
                              [date] =&gt; 2019-11-05 17:00:00.000000
                              [timezone_type] =&gt; 1
                              [timezone] =&gt; +01:00
                          )
                  )
  
          )
  )
  </code></pre>
  
  <p>Now I would like know, which dates are missing.</p>
  
  <p>I try something like this:</p>
  
  <pre><code>for ($i = 0; $i &lt; 14; $i++) {
      $checkDate = DateTime::createFromFormat('Y-m-d H:i', date('Y-m-d H:i'))-&gt;add(new DateInterval("P".$i."D"));
  
      if(array_search($checkDate, array_column($freeTime, 'datum')) !== false) {
          echo "FOUND&lt;br /&gt;";
      } else {
          echo "Not Found&lt;br /&gt;";
      }
  }
  </code></pre>
  
  <p>But it is only echoing "not found".</p>