title: Ruby Rails Time.change not working as I would expect...I have checked the docs!
body: <p>I have a form that contains one date element and 3 time elements.  This is because 3 time events will occur on one date, and I don't want the user to have to input that date 3 times.</p>
  
  <p>On the server side, I would like to combine the one date with the 3 times to get 3 datetime objects.  I was thinking I could just do something like:</p>
  
  <pre><code>time_object.change(:day =&gt; date_object.day, :month =&gt; date_object.month, :year =&gt; date_object.year)
  </code></pre>
  
  <p>but this has not worked.  Here is a simple test I have written that I would expect to work:</p>
  
  <pre><code>  def before_validation
      logger.info("show_time = " + self.show_time.to_s)
      self.show_time.change(:year =&gt; 2012)
      self.show_time.change(:minute =&gt; 30)
      logger.info("show_time = " + self.show_time.to_s)
    end
  </code></pre>
  
  <p>The two print statements should be different, but they are the same. Does anyone know the best way to merge a Time and Date object?</p>