title: Get the last Sunday of the Month
body: <p>I'm using Chronic to get the last Sunday of the month of any given year.  It will gladly give me the <em>n</em>&zwnj;th Sunday, but not the last.  </p>
  
  <p>This works, but is not what I need:</p>
  
  <pre><code>Chronic.parse('4th sunday in march', :now =&gt; Time.local(2015,1,1))
  </code></pre>
  
  <p>This is what I need, but doesn't work:</p>
  
  <pre><code>Chronic.parse('last sunday in march', :now =&gt; Time.local(2015,1,1))
  </code></pre>
  
  <p>Is there any way around this apparent limitation?</p>
  
  <p><em><strong>UPDATE</em></strong>:  I'm upvoting the two answers below because they're both good, but I've already implemented this in "pure Ruby" (in 2 lines of code, besides the <code>require 'date'</code> line), but I'm trying to demonstrate to management that Ruby is the right language to use to replace a Java codebase that is going away (and which had dozens of lines of code to compute this), and I told one manager that I probably could do it in one line of Ruby, and it would be readable and easy to maintain.</p>