//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(paraYear,paraMonth){

var monthStartDate = new Date(paraYear, paraMonth, 1);

var monthEndDate = new Date(paraYear, paraMonth + 1, 1);

var　 days　 =　 (monthEndDate　 -　 monthStartDate)/(1000　 *　 60　 *　 60　 *　 24);

return　 days;

}

//获得某周的开始日期

function getWeekStartDate(paraYear,paraMonth,paraDay,paraDayOfWeek) {

var weekStartDate = new Date(paraYear, paraMonth, paraDay + 1 - paraDayOfWeek);

return formatDate(weekStartDate);

}

//获得某周的结束日期

function getWeekEndDate(paraYear,paraMonth,paraDay,paraDayOfWeek) {

var weekEndDate = new Date(paraYear, paraMonth, paraDay + (7 - paraDayOfWeek));

return formatDate(weekEndDate);

}

//获得某月的开始日期

function getMonthStartDate(paraYear,paraMonth){

var monthStartDate = new Date(paraYear, paraMonth, 1);

return formatDate(monthStartDate);

}

//获得某月的结束日期

function getMonthEndDate(paraYear,paraMonth){

var monthEndDate = new Date(paraYear,paraMonth, getMonthDays(paraYear,paraMonth));

return formatDate(monthEndDate);

}

//获得上月开始时间

function getLastMonthStartDate(paraYear, lastMonth){

var lastMonthStartDate = new Date(paraYear, lastMonth, 1);

return formatDate(lastMonthStartDate);

}

//获得上月结束时间

function getLastMonthEndDate(paraYear, lastMonth, lastMonth){

var lastMonthEndDate = new Date(paraYear, lastMonth, getMonthDays(lastMonth));

return formatDate(lastMonthEndDate);

}

//获得某季度的开始日期

function getQuarterStartDate(paraYear,paraSeason){

switch (paraSeason){

case '1' : return paraYear+"-01-01";

case '2' : return paraYear+"-04-01";

case '3' : return paraYear+"-07-01";

case '4' : return paraYear+"-10-01";

}

}

//获得某季度的结束日期

function getQuarterEndDate(paraYear,paraSeason){

switch (paraSeason){

case '1' : return paraYear+"-03-31";

case '2' : return paraYear+"-06-30";

case '3' : return paraYear+"-09-30";

case '4' : return paraYear+"-12-31";

}

}

//获取某年某周的开始日期

function getBeginDateOfWeek(paraYear, weekIndex){

var firstDay = GetFirstWeekBegDay(paraYear);

//7*24*3600000 是一星期的时间毫秒数,(JS中的日期精确到毫秒)

var time=(weekIndex-1)*7*24*3600000;

var beginDay = firstDay;

//为日期对象 date 重新设置成时间 time

beginDay.setTime(firstDay.valueOf()+time);

return formatDate(beginDay);

}

//获取某年某周的结束日期

function getEndDateOfWeek(paraYear, weekIndex){

var firstDay = GetFirstWeekBegDay(paraYear);

//7*24*3600000 是一星期的时间毫秒数,(JS中的日期精确到毫秒)

var time=(weekIndex-1)*7*24*3600000;

var weekTime = 6*24*3600000;

var endDay = firstDay;

//为日期对象 date 重新设置成时间 time

endDay.setTime(firstDay.valueOf()+weekTime+time);

return formatDate(endDay);

}

//获取日期为某年的第几周

function GetWeekIndex(dateobj) {

var firstDay = GetFirstWeekBegDay(dateobj.getFullYear());

if (dateobj < firstDay) {

firstDay = GetFirstWeekBegDay(dateobj.getFullYear() - 1);

}

d = Math.floor((dateobj.valueOf() - firstDay.valueOf()) / 86400000);

return Math.floor(d / 7) + 1;

}

//获取某年的第一天

function GetFirstWeekBegDay(year) {

var tempdate = new Date(year, 0, 1);

var temp = tempdate.getDay();

if (temp == 1){

return tempdate;

}

temp = temp == 0 7 : temp;

tempdate = tempdate.setDate(tempdate.getDate() + (8 - temp));

return new Date(tempdate);

}