<script type="text/javascript" src="jquery.pasttimes.js"></script>

$(function(){
  $('#past').pasttimes();
});

<div class="past1">
  發表於  <a href="javascript:;" class="past" title="<?php echo date('Y-m-d H:i:s', time() - 300); ?>"></a>.
</div>

$('.past1').pasttimes({
  target: 'a.past',
  label: [' 秒前', ' 分鐘前', ' 小時前', ' 天前']
});

<div class="past2">
  Post at  <span class="past" title="<?php echo date('Y-m-d H:i:s', time() - 3600); ?>"></span>.
</div>

$('.past2').pasttimes({
  format: 'j M Y H:i:s',
  ontimeup: function () {
    console.log('Time\'s up');
  }
});
$(':button').click(function () {
  $('.past2').pasttimes('destroy');
});