以下实例设置月份为 4 (4月份) 日期为20号 - 在线编辑器

<!DOCTYPE html>
<html>
<body>

  <p id="demo">Click the button to display the date after changing the month and day.</p>

  <button onclick="myFunction()">Try it</button>

  <script>
    function myFunction() {
      var d = new Date();
      d.setUTCMonth(4, 20);
      var x = document.getElementById("demo");
      x.innerHTML = d;
    }
  </script>

</body>
</html>
​x
 
<!DOCTYPE html>
<html>
<body>
​
  <p id="demo">Click the button to display the date after changing the month and day.</p>
​
  <button onclick="myFunction()">Try it</button>
​
  <script>
    function myFunction() {
      var d = new Date();
      d.setUTCMonth(4, 20);
      var x = document.getElementById("demo");
      x.innerHTML = d;
    }
  </script>
​
</body>
</html>