JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://arshaw.com/js/fullcalendar-1.5.3/fullcalendar/fullcalendar.css">
<script src="http://www.arshaw.com/js/fullcalendar-1.5.3/fullcalendar/fullcalendar.min.js"></script>
<script src="http://arshaw.com/js/fullcalendar-1.5.4/fullcalendar/gcal.js"></script>
<button id="test1">Test1</button>
<br>
<br>
<div style="border:solid 2px red;">
    <div id='calendar'></div>
</div>

JavaScript

$(document).ready(function () {
    var date = new Date();
    var d = date.getDate();
    var m = date.getMonth();
    var y = date.getFullYear();

    var events_array = [{
        title: 'Test1',
        start: new Date(2019, 1, 1),
        allDay: false
    }, {
        title: 'Test2',
        start: new Date(2019, 1, 2),
        allDay: true
    }];

    $('#calendar').fullCalendar({
        header: {
            left: 'prev,next today',
            center: 'title',
            right: 'month,agendaWeek,agendaDay'
        },
        defaultView: 'month',
        events: events_array
    });
    
    alert("removing");
    $('#calendar').fullCalendar( 'removeEvents', function(event) {
        console.log(event.start.toDateString()===new Date(2013, 1,1).toDateString());
        if(event.start.toDateString()===new Date(2013, 1,1).toDateString())
            return true;
    });
});