var d = new Date(),
	year = d.getFullYear(),
 	month = d.getMonth(),
 	week = d.getDay(),
 	day = d.getDate(),
	monthDay = new Array(31,28,31,30,31,30,31,31,30,31,30,31),
	weekDay = "",
	isLeapYear = false;  //是否为闰年
将数字转换为汉字，因此用了一个switch的转换
switch(week) {
	case 0:
		weekDay = "日";
		break;
	case 1:
		weekDay = "一";
		break;
	case 2:
		weekDay = "二";
		break;
	case 3:
		weekDay = "三";
		break;
	case 4:
		weekDay = "四";
		break;
	case 5:
		weekDay = "五";
		break;
	case 6:
		weekDay = "六";
		break;
}
判断是否为闰年，大家应该都不陌生吧
if( ((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0) ) {
	isLeapYear = true;
}
循环计算天数
function getCurrentDay(theMonth,theDay) {
	var currentDay = 0;
	for(var i = 0;i < monthDay.length;i++) {
		if(i < theMonth) {
			if(isLeapYear && i == 1) {
				currentDay = currentDay + 29;
			}
			else {
				currentDay = currentDay + monthDay[i];
			}
		}
		if(i == theMonth) {
			currentDay = currentDay + theDay;
		}
	}
	return currentDay;
}
//我们学校忘记是什么时候开学的了，大致记得是2.24开始的第一周，因此这里是把3.24之前的天数减去
var nowDay = getCurrentDay(month,day),
	initialDay = getCurrentDay(1,23),
	weekYear = parseInt((nowDay - initialDay) / 7);
	if(week != 6) {
		weekYear = weekYear + 1;
	}
	var today = document.getElementById("today");
	today.innerHTML = "今天是" + (month + 1) + "月" + day + "日" + "<span style="margin-left: 15px;">" + "星期" + weekDay + "</span>" + "<span style="margin-left: 15px;">" + "第" + weekYear + "周" + "</span>";