title: How to start calendar_for week on Monday instead of Sunday?
body: <p>I was following the railscast <a href="http://railscasts.com/episodes/213-calendars" rel="nofollow">http://railscasts.com/episodes/213-calendars</a> and I use the following gem instead of script/plugin install 
  <a href="https://github.com/jchunky/table_builder" rel="nofollow">https://github.com/jchunky/table_builder</a></p>
  
  <p>The output is fine.. displays me a nice calendar! (thanks ryan)
  but I would like to know how to modify this code to make the week displayed starting on mondays instead of sundays:</p>
  
  <pre><code>&lt;div id="calendar"&gt;
    &lt;h2 id="month"&gt;
      &lt;%= link_to "&lt;", :month =&gt; (@date.beginning_of_month-1).strftime("%Y-%m-%d") %&gt;
      &lt;%=h @date.strftime("%B %Y") %&gt;
      &lt;%= link_to "&gt;", :month =&gt; (@date.end_of_month+1).strftime("%Y-%m-%d") %&gt;
    &lt;/h2&gt;
    &lt;% calendar_for @hours, :year =&gt; @date.year, :month =&gt; @date.month do |calendar| %&gt;
      &lt;%= calendar.head('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday') %&gt;
      &lt;% calendar.day(:day_method =&gt; :date) do |date, hours| %&gt;
        &lt;%= date.day %&gt;
        &lt;ul&gt;
          &lt;% for hour in hours %&gt;
            &lt;li&gt;&lt;%= link_to h(hour.task), hour %&gt;&lt;/li&gt;
          &lt;% end %&gt;
        &lt;/ul&gt;
      &lt;% end %&gt;
    &lt;% end %&gt;
  &lt;/div&gt;
  </code></pre>