简单了解下new Date()
var myDate = new Date();
myDate.getYear(); //获取当前年份(2位)
myDate.getFullYear(); //获取完整的年份(4位,1970-????)
myDate.getMonth(); //获取当前月份(0-11,0代表1月) // 所以获取当前月份是myDate.getMonth()+1;
myDate.getDate(); //获取当前日(1-31)
myDate.getDay(); //获取当前星期X(0-6,0代表星期天)
myDate.getTime(); //获取当前时间(从1970.1.1开始的毫秒数)
myDate.getHours(); //获取当前小时数(0-23)
myDate.getMinutes(); //获取当前分钟数(0-59)
myDate.getSeconds(); //获取当前秒数(0-59)
myDate.getMilliseconds(); //获取当前毫秒数(0-999)
myDate.toLocaleDateString(); //获取当前日期
var mytime=myDate.toLocaleTimeString(); //获取当前时间
myDate.toLocaleString( ); //获取日期与时间
2017年高考倒计时：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>countdown</title>
</head>
<body>
<p id="countdown"></p>
<script>
function countDown() {
var currentDate = new Date(),
endDate = new Date("2017/6/7,9:00"),
leftTime = endDate - currentDate,
leftDay = checkNum(parseInt(leftTime / (1000 * 60 * 60 * 24))),
leftHours = checkNum(parseInt(leftTime / (1000 * 60 * 60) % 24)),
leftMinutes = checkNum(parseInt(leftTime / (1000 * 60) % 60)),
leftSeconds = checkNum(parseInt(leftTime / 1000 % 60)),
countDown = document.getElementById('countdown');
countDown.innerHTML = '高考倒计时:' + leftDay + '天' + leftHours + '小时' + leftMinutes + '分' + leftSeconds + '秒'
// 判断是否小于零
function checkNum(num){
if(num<10){
num = '0' + num;
}
return num;
}
// 判断是否到达节点 清除定时器
if(leftTime<0){
countDown.innerHTML = '高考已经开始，等待你们的好消息！'
clearInterval(timer);
}
}
var timer;
timer = setInterval(countDown,500)
</script>
</body>
</html>