JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.14.1/moment.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.0.0/fullcalendar.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.0.0/fullcalendar.min.js"></script>
<div id='calendar'></div>

JavaScript

$('#calendar').fullCalendar({
  events: dowEvents
});

function dowEvents(start, end, tz, callback) {
  var events = [];
  var curr = start;
  while (curr <= end) {
    if (curr.format('dddd') === 'Monday') {
      events.push({
        title: 'Monday event',
        start: moment(curr)
      });
    }
    curr = curr.add(1, 'day');
  }
  callback(events);
}