JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/2.4.0/fullcalendar.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.6/moment.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/2.4.0/fullcalendar.js"></script>
<script src="https://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
	<div id='wrap'>

		<div id='external-events'>
			<h4>Draggable Events</h4>
			<div class='fc-event'>My Event 1</div>
			<div class='fc-event'>My Event 2</div>
			<div class='fc-event'>My Event 3</div>
			<div class='fc-event'>My Event 4</div>
			<div class='fc-event'>My Event 5</div>
			<p>
				<input type='checkbox' id='drop-remove' />
				<label for='drop-remove'>remove after drop</label>
			</p>
		</div>

		<div id='calendar'></div>

		<div style='clear:both'></div>

	</div>

CSS

body {
		margin-top: 40px;
		text-align: center;
		font-size: 14px;
		font-family: "Lucida Grande",Helvetica,Arial,Verdana,sans-serif;
	}
		
	#wrap {
		width: 1100px;
		margin: 0 auto;
	}
		
	#external-events {
		float: left;
		width: 150px;
		padding: 0 10px;
		border: 1px solid #ccc;
		background: #eee;
		text-align: left;
	}
		
	#external-events h4 {
		font-size: 16px;
		margin-top: 0;
		padding-top: 1em;
	}
		
	#external-events .fc-event {
		margin: 10px 0;
		cursor: pointer;
	}
		
	#external-events p {
		margin: 1.5em 0;
		font-size: 11px;
		color: #666;
	}
		
	#external-events p input {
		margin: 0;
		vertical-align: middle;
	}
	#calendar {
		float: right;
		width: 900px;
	}
    /* SHADE DAYS IN THE PAST */
    td.fc-day.fc-past {
        background-color: #EEEEEE;
    }

JavaScript

/*
	https://github.com/fullcalendar/fullcalendar/blob/master/demos/external-dragging.html
*/

	$(document).ready(function() {
		/* initialize the external events
		-----------------------------------------------------------------*/
		$('#external-events .fc-event').each(function() {
			// store data so the calendar knows to render an event upon drop
			$(this).data('event', {
				title: $.trim($(this).text()), // use the element's text as the event title
				stick: true // maintain when user navigates (see docs on the renderEvent method)
			});
			// make the event draggable using jQuery UI
			$(this).draggable({
				zIndex: 999,
				revert: true,      // will cause the event to go back to its
				revertDuration: 0  //  original position after the drag
			});
		});
		/* initialize the calendar
		-----------------------------------------------------------------*/
		$('#calendar').fullCalendar({
			header: {
				left: 'prev,next today',
				center: 'title',
				right: 'month,agendaWeek,agendaDay'
			},
			editable: true,
			droppable: true, // this allows things to be dropped onto the calendar
			drop: function() {
				// is the "remove after drop" checkbox checked?
				if ($('#drop-remove').is(':checked')) {
					// if so, remove the element from the "Draggable Events" list
					$(this).remove();
				}
			},
            /* This constrains it to today or later */
            eventConstraint: {
                start: moment().format('YYYY-MM-DD'),
                end: '2100-01-01' // hard coded goodness unfortunately
            }
		});
	});