Someone

<html>
  <head>
    <title tal:content="template/title">The title</title>
  </head>
  <body>

<script language="JavaScript">
function FormataData(Campo,teclapres)
{
var tecla = teclapres.keyCode;
vr = document.form[Campo].value;
vr = vr.replace( ".", "" );
vr = vr.replace( "/", "" );
vr = vr.replace( "/", "" );
tam = vr.length + 1;
if( tecla != 9 && tecla != 8 )
{
if( tam > 2 && tam < 5 )
document.form[Campo].value = vr.substr( 0, tam - 2 ) + '/' + vr.substr( tam - 2, tam );
if( tam >= 5 && tam <= 10 )
document.form[Campo].value = vr.substr( 0, 2 ) + '/' + vr.substr( 2, 2 ) + '/' + vr.substr( 4, 4 );
}
}
</script>

<fieldset>
    <legend style="border:1px solid gray;font-family:'verdana',arial,times;font-size:10pt;padding:5px 5px 5px 5px;">Acompanhamento de Ordem de Carregamento de Grãos</legend>
        <form method="post" tal:attributes="action string:${context/absolute_url}/acompanhamento_ordem_carregamento_graos_py">

            <table>
                <tr>
                    <td><span style="font-family:verdana;font-size:8pt;">Fechada</span><input type="radio" name="grupo1" value="fechada">
                        <span style="font-family:verdana;font-size:8pt;margin-left:1em;">Andamento</span><input type="radio" name="grupo1" value="andamento">
                    </td>
                    <td>Data Inicial<input type="text" maxlength="10" id="dataI" name="dataI" size="10" onkeypress="FormataData('dataI',event);"></td>
                    <td>Data Final<input type="text" maxlength="10" name="dataF" size="10"></td>
                    <td><input type="submit" value="Processar"></td>
                </tr>
            </table>
        </form>
</fieldset>
                           
  </body>
</html>