Rename Mes to pt_BR

Question

So Galera, I have this doubt if there is how to change the name of the month, as in the image change from Feb/15 to Feb/15

Code:

<?php $cronog = $editais->listarCronogEditalVigente();
    setlocale (LC_ALL, 'pt_BR');
    if($cronog[0]->inicioPesquisaProjeto <= $cronog[0]->terminoPesquisaProjeto):

      $timestamp1 = strtotime($cronog[0]->inicioPesquisaProjeto);
      $timestamp2 = strtotime($cronog[0]->terminoPesquisaProjeto);

      while ($timestamp1 <= $timestamp2):
        $data = date( 'M/y', $timestamp1 );
          $data1 = date( 'm-y', $timestamp1 );
        $timestamp1 += 2707200; ?>
        <script>
          var thAno = $('#barra');
          var campSelect = $('#metas1');
          $(thAno).append('<th class="text-center"><?= $data ?></th>');
          $(campSelect).append('<td class="text-center" id="<?php echo($data1); ?>"></td>');
        </script>
<?php endwhile;
    endif;
?>