JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://fullcalendar.io/js/fullcalendar-2.1.1/fullcalendar.css">
<script src="http://fullcalendar.io/js/fullcalendar-2.1.1/lib/moment.min.js"></script>
<script src="http://fullcalendar.io/js/fullcalendar-2.1.1/fullcalendar.min.js"></script>
<script src="http://students.ashreinu.org.il/includes/kdate.js"></script>
<p>I am trying to add a line of content to each cell - which is basically the date of the cell - converted to the Hebrew date (which be displayed next to the regular date number)</p><div id='calendar'></div>

JavaScript

$(document).ready(function() {
		
		$('#calendar').fullCalendar({
			header: {
				left: 'prev,next today',
				center: 'title',
				right: 'month,basicWeek,basicDay'
			},
            dayRender: function (date, cell) {

			
				var cellYear = date.year();
                var cellMonth = date.month() + 1;
                
                var cellDay = date.date();
                cell.prepend(cellDay  +'-'+cellMonth+'-'+cellYear)
                
               // cell.prepend('<span class="hebDateInCell">' + ReturHebDate(cellDay,cellMonth,cellYear) + '</span>');
				
			
			},
			defaultDate: '2014-09-12',
			editable: true,
			eventLimit: true, // allow "more" link when too many events
			events: [
				{
					title: 'All Day Event',
					start: '2014-09-01'
				},
				{
					title: 'Long Event',
					start: '2014-09-07',
					end: '2014-09-10'
				},
				{
					id: 999,
					title: 'Repeating Event',
					start: '2014-09-09T16:00:00'
				},
				{
					id: 999,
					title: 'Repeating Event',
					start: '2014-09-16T16:00:00'
				},
				{
					title: 'Conference',
					start: '2014-09-11',
					end: '2014-09-13'
				},
				{
					title: 'Meeting',
					start: '2014-09-12T10:30:00',
					end: '2014-09-12T12:30:00'
				},
				{
					title: 'Lunch',
					start: '2014-09-12T12:00:00'
				},
				{
					title: 'Meeting',
					start: '2014-09-12T14:30:00'
				},
				{
					title: 'Happy Hour',
					start: '2014-09-12T17:30:00'
				},
				{
					title: 'Dinner',
					start: '2014-09-12T20:00:00'
				},
				{
					title: 'Birthday Party',
					start: '2014-09-13T07:00:00'
				},
				{
					title: 'Click for Google',
					url: 'http://google.com/',
					start: '2014-09-28'
				}
			]
		});
		
	});