将本地时间转换为UTC时间

<p id="demo">单击按钮以显示当地时间,使用UTC日期-时间。</p>

<button onclick="myFunction()">点我</button>

<script>

  function myFunction() {

    var d = new Date(Date.UTC(2012, 02, 30));

    var x = document.getElementById("demo");

    x.innerHTML = d;

  }

</script>