function counter() {
	var date = new Date();
	var year = date.getFullYear();
	var date2 = new Date(year, 12, 31, 23, 59, 59);
	/*转换成秒*/
	var time = (date2 - date) / 1000;
	var day = Math.floor(time / (24 * 60 * 60))
	var hour = Math.floor(time % (24 * 60 * 60) / (60 * 60))
	var minute = Math.floor(time % (24 * 60 * 60) % (60 * 60) / 60);
	var second = Math.floor(time % (24 * 60 * 60) % (60 * 60) % 60);
	var str = year + "年还剩" + day + "天" + hour + "时" + minute + "分" + second + "秒";
	console.log(str);
}
window.setInterval("counter()", 1000);javascript 网页中实现一个计算当年还剩多少时间的倒数计时程序
原文:http://blog.csdn.net/primary_wind/article/details/40091407