js 倒计时

1. 60s 倒计时

var clicking;//防止重复点击

function taketime(obj) {
    var timeInterval; //定时任务

    if (clicking) {
        return;
    }

    var number = 60;
    timeInterval= window.setInterval(function () {
        if (number <= 0) {
            obj.html("发送验证码");
            window.clearInterval(timeInterval);
            clicking = false;
        } else {
            clicking = true;
            obj.html(number -= 1).append(" s后重发");//.......每秒内容更改
        }
    }, 1000);
}

2. 天数、时、分、秒

//html

<body onload="leftTimer()">

//js
function leftTimer(year,month,day,hour,minute,second){ 
 var leftTime = (new Date(year,month-1,day,hour,minute,second)) - (new Date()); //计算剩余的毫秒数 
 var days = parseInt(leftTime / 1000 / 60 / 60 / 24 , 10); //计算剩余的天数 
 var hours = parseInt(leftTime / 1000 / 60 / 60 % 24 , 10); //计算剩余的小时 
 var minutes = parseInt(leftTime / 1000 / 60 % 60, 10);//计算剩余的分钟 
 var seconds = parseInt(leftTime / 1000 % 60, 10);//计算剩余的秒数 
 days = checkTime(days); 
 hours = checkTime(hours); 
 minutes = checkTime(minutes); 
 seconds = checkTime(seconds); 
 setInterval("leftTimer(2016,11,11,11,11,11)",1000); 
 document.getElementById("timer").innerHTML = days+"天" + hours+"小时" + minutes+"分"+seconds+"秒"; 
} 
function checkTime(i){ //将0-9的数字前面加上0，例1变为01 
 if(i<10) 
 { 
  i = "0" + i; 
 } 
 return i; 
}