JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.8.1/jquery.validate.js"></script>
<form id="myform">
<div class="dropdown">
  <select id="day" class="styled required" name="day">
    <option value="">--</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>

  </select>
</div>
<div class="dropdown">
  <select id="month" class="styled required" name="month">
    <option value="">--</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
    
  </select>
</div>
<div class="dropdown">
  <select id="year" class="styled required" name="year">
    <option value="">--</option>
    <option value="1993">1993</option>
    <option value="1992">1992</option>
    <option value="1991">1991</option>
    <option value="1990">1990</option>
 
  </select>
</div>
    <button>Submit</button>
</form>

JavaScript

$('button').click(function(){
    
    $('#myform').valid();
    return false;
        });