title: how to add class in fullcalendar
body: <p>i need to add class for specific booked and blocked days in fullcalendar, i need to highlight the booked and blocked days with different color. Try tried out with some code but not coming correctly</p>
  
  <pre><code>$("#calendar").fullCalendar({
      header: {
          left:   'title',
          center: '',
          right:  'prev,next'
      },
      selectable: true,
      events:[
          {
              title: 'Booked',
              start: '2017-03-11',
              end: '2017-03-22'
          },
          {
              title: 'Block',
              start: '2017-03-28',
              end: '2017-04-6'
          }
      ]
  });
  </code></pre>