title: PHP strtotime Function: first day of this year
body: <p>I am testing some code using PHP’s <code>strtotime()</code> function, but I can’t work out how PHP is interpreting the following:</p>
  
  <pre><code>strtotime('first day of this year')
  </code></pre>
  
  <p>I get <code>Tue Sep 01 2015</code> (currently it is Sunday 27 September in Australia).</p>
  
  <p>Is this some strange new usage of “year” that I was previously unaware of?</p>