JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <head>
    <meta charset='utf-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1, shrink-to-fit=no'>
    <meta http-equiv='x-ua-compatible' content='ie=edge'>
    <!--1. Link VCalendar CSS-->
    <link rel='stylesheet' href='https://unpkg.com/v-calendar/lib/v-calendar.min.css'>
  </head>
  <body>
    <div id='app'>
      <v-date-picker @dayclick="dayClick" :mode='mode' v-model='selectedDate'></v-date-picker>
      <div>
        {{ selectedDate }}
      </div>
    </div>
    <!--2. Link Vue Javascript-->
    <script src='https://unpkg.com/vue/dist/vue.js'></script>
    <!--3. Link VCalendar Javascript (Plugin automatically installed)-->
    <script src='https://unpkg.com/v-calendar'></script>
    <!--4. Create the Vue instance-->
    <script>
      new Vue({
        el: '#app',
        data: {
          // Data used by the date picker
          mode: 'single',
          selectedDate: new Date(),
        },
        methods: {
        	dayClick () {
          	console.log(this.selectedDate)
          }
        }
      })
    </script>
  </body>
</html>