/**
 * 获取本周、本季度、本月、上月的开始日期、结束日期
 */
var now = new Date(); //当前日期
var nowDayOfWeek = now.getDay(); //今天本周的第几天
var nowDay = now.getDate(); //当前日
var nowMonth = now.getMonth(); //当前月
var nowYear = now.getYear(); //当前年
nowYear += (nowYear < 2000) ? 1900 : 0; //
var lastMonthDate = new Date(); //上月日期
lastMonthDate.setDate(1);
lastMonthDate.setMonth(lastMonthDate.getMonth() - 1);
var lastYear = lastMonthDate.getYear();
var lastMonth = lastMonthDate.getMonth();
//格式化日期：yyyy-MM-dd
function formatDate(date) {
	var myyear = date.getFullYear();
	var mymonth = date.getMonth() + 1;
	var myweekday = date.getDate();
	if (mymonth < 10) {
		mymonth = "0" + mymonth;
	}
	if (myweekday < 10) {
		myweekday = "0" + myweekday;
	}
	return (myyear + "-" + mymonth + "-" + myweekday);
}
//获得某月的天数
function getMonthDays(myMonth) {
	var monthStartDate = new Date(nowYear, myMonth, 1);
	var monthEndDate = new Date(nowYear, myMonth + 1, 1);
	var days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
	return days;
}
//获得本季度的开始月份
function getQuarterStartMonth() {
	var quarterStartMonth = 0;
	if (nowMonth < 3) {
		quarterStartMonth = 0;
	}
	if (2 < nowMonth && nowMonth < 6) {
		quarterStartMonth = 3;
	}
	if (5 < nowMonth && nowMonth < 9) {
		quarterStartMonth = 6;
	}
	if (nowMonth > 8) {
		quarterStartMonth = 9;
	}
	return quarterStartMonth;
}
//获得本周的开始日期
function getWeekStartDate() {
	var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);
	return formatDate(weekStartDate);
}
//获得本周的结束日期
function getWeekEndDate() {
	var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));
	return formatDate(weekEndDate);
}
//获得上周的开始日期
function getLastWeekStartDate() {
	var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 7);
	return formatDate(weekStartDate);
}
//获得上周的结束日期
function getLastWeekEndDate() {
	var weekEndDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 1);
	return formatDate(weekEndDate);
}
//获得本月的开始日期
function getMonthStartDate() {
	var monthStartDate = new Date(nowYear, nowMonth, 1);
	return formatDate(monthStartDate);
}
//获得本月的结束日期
function getMonthEndDate() {
	var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
	return formatDate(monthEndDate);
}
//获得上月开始时间
function getLastMonthStartDate() {
	var lastMonthStartDate = new Date(nowYear, lastMonth, 1);
	return formatDate(lastMonthStartDate);
}
//获得上月结束时间
function getLastMonthEndDate() {
	var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth));
	return formatDate(lastMonthEndDate);
}
//获得本季度的开始日期
function getQuarterStartDate() {
	var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);
	return formatDate(quarterStartDate);
}
//或的本季度的结束日期
function getQuarterEndDate() {
	var quarterEndMonth = getQuarterStartMonth() + 2;
	var quarterStartDate = new Date(nowYear, quarterEndMonth,
			getMonthDays(quarterEndMonth));
	return formatDate(quarterStartDate);
}