javascript 自带有个对象(构造函数)，Date().下面是代码：
回答一：
var now = new Date();
var nowTime = now.toLocaleString(); var date = nowTime.substring(0,10);//截取日期 var time = nowTime.substring(10,20); //截取时间 var week = now.getDay(); //星期 var hour = now.getHours(); //小时 回答二：
var date = new Date();
var year = date.getFullYear();
var month = date.getMonth()+1;var day = date.getDate();var hour = date.getHours();var minute = date.getMinutes();var second = date.getSeconds();alert(year+'年'+month+'月'+day+'日 '+hour':'+minute+':'+second)回答三：
function showTime() {
var now = new Date(); var nowTime = now.toLocaleString(); var date = nowTime.substring(0,10);//截取日期 var time = nowTime.substring(10,20); //截取时间 var week = now.getDay(); //星期 var hour = now.getHours(); //小时 //判断星期几 var weeks = ["日","一","二","三","四","五","六"]; var getWeek = "星期" + weeks[week]; var sc; //判断是AM or PM if(hour >= 0 && hour < 5){ sc = '凌晨'; } else if(hour > 5 && hour <= 7){ sc = '早上'; } else if(hour > 7 && hour <= 11){ sc = '上午'; } else if(hour > 11 && hour <= 13){ sc = '中午'; } else if(hour> 13 && hour <= 18){ sc = '下午'; } else if(hour > 18 && hour <= 23){ sc = '晚上'; } document.getElementById('time').innerHTML ="当前时间：" + date+" " + getWeek +" "+" "+sc+" "+time; setTimeout('showTime()',1000); } </script> 调用方法: <body onload="showTime()"> <div id="time"></div> </body>