title: PF Filtering a Datatable column which contains a date
body: <p>I have a column in a datatable and I want to add a filter with this code:</p>
  
  <pre><code>&lt;p:dataTable id="aDataTable" var="aVariable" value="#{aView.values}" paginator="true" rows="10" selectionMode="single" selection="#{aView.selection}" onRowSelectUpdate="aForm"&gt;
                   &lt;f:facet name="header"&gt;
                       A List
                   &lt;/f:facet&gt;
                &lt;p:column sortBy="#{aVariable.id}" filterBy="#{aVariable.id}" filterEvent="change"&gt;
                    &lt;f:facet name="header"&gt;
                        &lt;h:outputText value="No"/&gt;
                    &lt;/f:facet&gt;
                     &lt;h:outputText value="#{aVariable.id}"/&gt;
                &lt;/p:column&gt;
                &lt;p:column sortBy="#{aVariable.date}" filterBy="#{aVariable.date}" filterEvent="change"&gt;
                    &lt;f:facet name="header"&gt;
                        &lt;h:outputText value="Date"/&gt;
                    &lt;/f:facet&gt;
  &lt;/p:dataTable&gt;
  </code></pre>
  
  <p>date is inputted in a form in this format:</p>
  
  <pre><code>&lt;h:outputText value="Date: *"/&gt;
  &lt;p:calendar pattern="dd/MM/yyyy" value="#{aView.value.date}"/&gt;
  </code></pre>
  
  <p>Filter is working for id but not for date. What is the reason for this and how can I make filter work in this case?</p>