<p id="demo">单击按钮显示给定时间中一周的某天（UTC）</p>

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

<script>

function myFunction(){

    var d=new Date();

    var weekday=new Array(7);

    weekday[0]="周日";

    weekday[1]="周一";

    weekday[2]="周二";

    weekday[3]="周三";

    weekday[4]="周四";

    weekday[5]="周五";

    weekday[6]="周六";

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

    x.innerHTML=weekday[d.getUTCDay()];

}

</script>

<p><strong>注意:</strong> 0=周日, 1=周一, 类推</p>