title: How to periodically set state?
body: <p>I am trying to build a countdown app for special days for example 11 d 2 h 30 m 23s to the new year but I can't reload my state every second so it just shows me the second that I loaded the page I don't know how to dynamically reload the page. </p>
  
  <pre><code> import 'package:flutter/material.dart';
  
      class RopSayac extends StatefulWidget {
        _RopSayacState createState() =&gt; _RopSayacState();
      }
  
      class _RopSayacState extends State&lt;RopSayac&gt; {
  
        var now = DateTime.now().second.toString();
        String asd(){
          setState(() {
          now = DateTime.now().second.toString();
  
          });
          return now;
        }
  
        @override
        Widget build(BuildContext context) {
  
  
          return Container(
            child: new Text(asd()),
          );
        }
      }
  </code></pre>
  
  <p>This is what I got and it doesn't reload time. I am pretty new on the flutter.</p>