<!DOCTYPE HTML>
<html>
<head>
  <title>Timeline | Custom function label format example</title>

  <style>
    body, html {
      font-family: arial, sans-serif;
      font-size: 11pt;
    }

    #visualization {
      box-sizing: border-box;
      width: 100%;
      height: 300px;
    }
  </style>

  <!-- note: moment.js must be loaded before vis.js, else vis.js uses its embedded version of moment.js -->
  <script src="http://cdnjs.cloudflare.com/ajax/libs/moment.js/2.8.4/moment.min.js"></script>

  <script