title: attr_accessor for a date and problems using select_date
body: <p>I'm trying to use attr_accessor for a date which normally works fine except when I attempt to use it with the select_date helper method.</p>
  <p>Looking at the code behind the helper method I'm guessing it looks for the table column with date type.  And in this case since there is no table it's not handling it correctly and I get:</p>
  <h1>ActiveRecord::MultiparameterAssignmentErrors</h1>
  <pre><code>&quot;search&quot;=&gt;{&quot;number_of_days&quot;=&gt;&quot;3&quot;,
   &quot;searchable_id&quot;=&gt;&quot;6933&quot;,
   &quot;startdate(1i)&quot;=&gt;&quot;2011&quot;,
   &quot;startdate(2i)&quot;=&gt;&quot;2&quot;,
   &quot;startdate(3i)&quot;=&gt;&quot;11&quot;}}
  </code></pre>
  <p>Is there a way around this?  Or do I need to create some kind of before filter in the controller?  I'd prefer doing it on the model level, but I'm not sure how to handle this case?  An attr_accessor for each seems a bit over kill.  Anyone else have an elegant solution?</p>