Full calendar - add text to day when there is no event

Question

Would it be possible to add background text in full calendar when there is no event found for day, need help please

e.g

Answer 1

Just an idea:

$('#calendar').fullCalendar({

  defaultView: 'month',
  events: [{
    title: 'event',
    start: '2017-01-05 11:00',
    end: '2017-01-06 13:00',
  }, {
    title: 'event 2',
    start: '2017-01-18'
  }],
  dayRender: function(date, cell) {
    cell.append('<div class="unavailable">Unavailable</div>');
  },
  eventAfterAllRender: function(view) {
    var dayEvents = $('#calendar').fullCalendar('clientEvents', function(event) {
      if (event.end) {
        var dates = getDates(event.start, event.end);
        $.each(dates, function(index, value) {
          var td = $('td.fc-day[data-date="' + value + '"]');
          td.find('div:first').remove();
        });
      } else {
        var td = $('td.fc-day[data-date="' + event.start.format('YYYY-MM-DD') + '"]');
        td.find('div:first').remove();
      }
    });
  }
});

function getDates(startDate, endDate) {
  var now = startDate,
    dates = [];

  while (now.format('YYYY-MM-DD') <= endDate.format('YYYY-MM-DD')) {
    dates.push(now.format('YYYY-MM-DD'));
    now.add('days', 1);
  }
  return dates;
};

Try this fiddle.