Cookies timer not working

Question

I created a cookie timer, and I am so new with cookie, plus i am not a pro with jquery so i created the below function.

1st it clears a particular box on click, but doesn't show up when i alter the cookie time, i don't know where the issue would certainly be from.

below is my code

jQuery(document).ready(function ($) {
  $('#close-even-more').click(function () {
    $('.even-more-sq-rt').hide();

    function display() { 
      var now = new Date();
      var time = now.getTime();
      var expireTime = time + 1000*30;
      now.setTime(expireTime);
      var tempExp = 'fri, 08 Dec 2017 05:03:17 GMT';
      document.cookie = 'cookie=ok;expires='+now.toGMTString()+';path=/';
      console.log(document.cookie);
    }
  });
});