做一个网页上的时钟

setInterval(function(){
    var date = new Date()
    var hour = date.getHours()
    var minute = date.getMinutes()
    var second = date.getSeconds()
    // document.write('现在是北京时间'+hour+'点'+minute+'分'+second+'秒');
    box.innerText = '现在是北京时间'+hour+'点'+minute+'分'+second+'秒'
},1000)