title: PHP stringtotime function first weekday
body: <pre><code>echo date("d-M-Y", strtotime("first monday 2019-07"));
  </code></pre>
  
  <p>Shouldn't the output of this line be 01-Jul-2019? Thats the first monday in July but the output is: 08-Jul-2019.</p>
  
  <p>What is the error im making?</p>