​x
 
<!DOCTYPE html>
<html>
<body>
​
<p>单击该按钮可在更改秒数后显示日期时间。</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var d = new Date();
  d.setUTCSeconds(35);
  document.getElementById("demo").innerHTML = d;
}
</script>
​
</body>
</html>
​