meu xtml
<?xml version='1.0' encoding='UTF-8' ?>  
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">  
<html xmlns="http://www.w3.org/1999/xhtml"  
      xmlns:h="http://java.sun.com/jsf/html"  
      xmlns:f="http://java.sun.com/jsf/facelets"  
      xmlns:p="http://primefaces.org/ui"  
      xmlns:c="http://java.sun.com/jsf/core">  
    <h:head>  
        <title> - SVP Sistema Venda de Passagens 0.1</title>  
        <link rel="stylesheet" href="../../css/bootstrap.css"></link>  
    </h:head>  
    <h:body>  
        <div id="bannerPag">  
            <f:insert name="bannerPag">  
                <f:include src="../banner/banner.xhtml" />  
            </f:insert>  
        </div>  
  
        <div class="container" style="padding-top: 80px;">  
            <div class="row" id="menuApp">  
                <f:insert>  
                    <f:include src="../menus/menuUserAdm.xhtml"/>  
                </f:insert>  
            </div>  
  
            <div id="cad">  
                <h:form styleClass="form-horizontal well" style="margin-left: -20px;" id="form">  
                    <fieldset>  
                        <legend>Consulta Lotação Rota</legend>  
  
                        <p:growl id="growl" showDetail="true" autoUpdate="true" life="10000" />  
  
                        <div class="control-group" style="padding-top: 40px;">  
                            <h:outputLabel value="Escolha a Rota" styleClass="control-label" />  
                            <div class="controls">  
                                <p:selectOneMenu value="#{consultaLotacaoController.idRotaAux}" style="width: 300px;" >  
                                      
                                    <c:selectItem itemLabel="Selecione a Rota..." itemValue="#{null}"/>  
                                    <c:selectItems value="#{consultaLotacaoController.listaRota}" var="r" itemLabel="#{r.dsRota}" itemValue="#{r.idRota}" />  
                                    <p:ajax event="change" process="@this" listener="#{consultaLotacaoController.searchRota}" update="panelDia"/>  
                                      
                                </p:selectOneMenu>  
                            </div>  
                        </div>  
  
                        <div class="control-group">  
                            <h:outputLabel value="Escolha o Dia" styleClass="control-label" />  
                            <div class="controls">  
                                <p:outputPanel id="panelDia" >  
                                    <p:selectOneMenu value="#{consultaLotacaoController.idDiaAux}" style="width: 300px;"   
                                                     disabled="#{consultaLotacaoController.idRotaAux == null}" >  
                                      
                                        <c:selectItem itemLabel="Selecione o Dia..." itemValue="#{null}" rendered="#{consultaLotacaoController.idRotaAux != null}"/>  
                                        <c:selectItems value="#{consultaLotacaoController.listaDiaDtoAux}" var="diaAux" itemValue="#{diaAux.idDia}"   
                                                       itemLabel="#{diaAux.label}" />  
  
                                        <p:ajax event="change" process="@this" listener="#{consultaLotacaoController.searchDia}" update="panelHorario"/>  
  
                                    </p:selectOneMenu>  
                                </p:outputPanel>  
                            </div>  
                        </div>  
  
                        <div class="control-group">  
                            <h:outputLabel value="Escolha o Horário" styleClass="control-label" />  
                            <div class="controls">  
                                <p:outputPanel id="panelHorario" >  
                                    <p:selectOneMenu value="#{consultaLotacaoController.horario.horario}" style="width: 300px;"  
                                                     disabled="#{consultaLotacaoController.idDiaAux == null}">  
  
                                        <c:selectItem itemLabel="Selecione o Horário..." itemValue="#{null}" rendered="#{consultaLotacaoController.idDiaAux != null}"/>  
                                        <c:selectItems value="#{consultaLotacaoController.dia.listaHorarios}" var="h" itemLabel="#{h.horaFormatado}"   
                                                       itemValue="#{h.horario}"/>  
  
                                    </p:selectOneMenu>  
                                </p:outputPanel>  
                            </div>  
                        </div>  
                          
                        <p:outputPanel id="panelVagas" rendered="#{consultaLotacaoController.numeroVagas != null}" autoUpdate="true">  
                            <div class="control-group">  
                                <h:outputLabel value="Número de vagas :" styleClass="control-label" />  
                                <div class="controls">  
                                    <h:outputLabel value="#{consultaLotacaoController.numeroVagas}" styleClass="control-label" />  
                                </div>  
                            </div>  
                        </p:outputPanel>  
  
                        <div class="form-actions">  
                            <p:commandButton value="Verficar Lotação" styleClass="btn btn-primary" actionListener="#{consultaLotacaoController.buscarVagas}"  
                                             update="panelVagas"/>  
                            <p:commandButton value="Limpar" styleClass="btn" style="margin-left: 10px;" actionListener="#{consultaLotacaoController.limpar}"  
                                             immediate="true" update=":form"/>  
                        </div>  
                    </fieldset>  
                </h:form>  
            </div>  
  
            <div id="foot">  
                <f:insert name="foot">  
                    <f:include src="../footer.xhtml"/>   
                </f:insert>  
            </div>  
        </div>  
    </h:body>  
</html>  Quando clico no botãao “Verificar Lotação” aparece esse erro
Erro de conversão ao definir o valor '08:30:00' para 'null Converter'.  
Erro de conversão ao definir o valor '08:30:00' para 'null Converter'.  O que faço para resolver ?