JSFiddle - React, Tailwind, and code Playground

CSS

body
{
    transition: background 0.5s linear;
    background-attachment: fixed;
    background-position: center; 
    background-size: 200px 200px;
}

body.background1
{
    background-image: url(http://subtlepatterns.com/patterns/congruent_outline.png);
}

body.background2
{
    background-image: url(http://subtlepatterns.com/patterns/footer_lodyas.png);
}

JavaScript

setInterval(function() {
   var $body = $('body');
   if($body.hasClass('background1'))
   {
       $body.removeClass('background1');
       $body.addClass('background2');
   }
  else {        
       $body.removeClass('background2');
       $body.addClass('background1');
    }
}, 1000);