title: The first day of the current month in php using date_modify as DateTime object
body: <p>I can get the Monday of this week with:</p>
  
  <pre><code>$monday = date_create()-&gt;modify('this Monday');
  </code></pre>
  
  <p>I would like to get with the same ease the 1st of this month. How can I achieve that?</p>