Primefaces dataTable sortBy a Date property - jsf-2

Question

I'm using a p:dataTable to display a list of objects and I would like to order them by their Date property in a descending manner here is the code:
<h:form id="receivablesForm">
<p:dataTable id="receivablesTable" value="#{receivableManager.overdueReceivables}" var="receivable" rows="18" emptyMessage="#{msg['warning.noData']}" style="width: 585px;" sortBy="#{receivable.dueDate}" sortOrder="descending">
<p:column sortBy="#{receivable.invoice.number}" styleClass="fixedSizeColumnSmall">
<f:facet name="header">
<h:outputText value="#{msg['label.number']}" />
</f:facet>
<h:outputText value="#{receivable.invoice.number}-#{receivable.number}" />
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="#{msg['label.clientName']}" />
</f:facet>
<h:outputText value="#{receivable.invoice.client.person.name}" />
</p:column>
<p:column styleClass="fixedSizeColumn">
<f:facet name="header">
<h:outputText value="#{msg['label.dueDate']}" />
</f:facet>
<h:outputText value="#{receivable.dueDate}" style="#{receivableManager.isOverdue(receivable) ? 'color: red' : ''}">
<f:convertDateTime pattern="dd/MM/yyyy" />
</h:outputText>
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="#{msg['label.amount']}" />
</f:facet>
<h:outputText value="#{receivable.amount}">
<f:convertNumber type="currency" locale="pt_br" />
</h:outputText>
</p:column>
</p:dataTable>
</h:form>
However the objects are not being ordered at all. Is it possible to order by a Date property in a descending manner using the sortBy and sortOrder properties?