title: Getting last month's date in php
body: <p>I want to get last month's date. I wrote this out:</p>
  
  <pre><code>$prevmonth = date('M Y');
  </code></pre>
  
  <p>Which gives me the current month/year.  I can't tell if I should use <code>strtotime</code>, <code>mktime</code>. Something to the timestamp? Do I need to add something afterwards to reset so that the date isn't set to last month throughout everything for all timestamps on my site? I'm trying to RTM but it's hard for me to figure this out.</p>