JavaScript日期操作（周，月，季度，年）

<mce:script type="text/javascript">

<!--

//当天

function showToDay()

{

var Nowdate=new Date();

M=Number(Nowdate.getMonth())+1

return Nowdate.getYear()+"-"+M+"-"+Nowdate.getDate();

}





//本周第一天

function showWeekFirstDay()



{

var Nowdate=new Date();

var WeekFirstDay=new Date(Nowdate-(Nowdate.getDay()-1)*86400000);

return WeekFirstDay;

}

//本周最后一天

function showWeekLastDay()

{

var Nowdate=new Date();

var WeekFirstDay=new Date(Nowdate-(Nowdate.getDay()-1)*86400000);

var WeekLastDay=new Date((WeekFirstDay/1000+6*86400)*1000);

return WeekLastDay;

}

//本月第一天

function showMonthFirstDay()

{

var Nowdate=new Date();

var MonthFirstDay=new Date(Nowdate.getYear(),Nowdate.getMonth(),1);

return MonthFirstDay;

}



//本月最后一天



function showMonthLastDay()

{

var Nowdate=new Date();

var tmpDate=new Date(Nowdate.getYear(),Nowdate.getMonth()+1,1);

//tmpDate.setDate(tmpDate.getDate() -1);

//return new Date(Nowdate.getYear(),Nowdate.getMonth(),tmpDate.getDate());

var MonthLastDay=new Date(tmpDate-86400000);

return MonthLastDay;



}





//本季第一天

function showquarterFirstDay()

{

var Nowdate=new Date();

if(Nowdate.getMonth()<3)

return new Date(Nowdate.getYear(),0,1);

else if(Nowdate.getMonth()>2 && Nowdate.getMonth()<6)

return new Date(Nowdate.getYear(),3,1);

else if(Nowdate.getMonth()>5 && Nowdate.getMonth()<9)

return new Date(Nowdate.getYear(),6,1);

else if(Nowdate.getMonth()>8)

return new Date(Nowdate.getYear(),9,1);

}



//本季最后一天

function showquarterLastDay()

{

var Nowdate=new Date();



if(Nowdate.getMonth()<3)

return new Date(Nowdate.getYear(),2,31);

else if(Nowdate.getMonth()>2 && Nowdate.getMonth()<6)

return new Date(Nowdate.getYear(),5,30);

else if(Nowdate.getMonth()>5 && Nowdate.getMonth()<9)

return new Date(Nowdate.getYear(),8,30);

else if(Nowdate.getMonth()>8)

return new Date(Nowdate.getYear(),11,31);

}





//本年第一天

function showyearFirstDay()

{

var Nowdate=new Date();

var yearFirstDay=new Date(Nowdate.getYear(),0,1);

return yearFirstDay;

}



//本年最后一天

function showyearLastDay()

{

var Nowdate=new Date();

var yearLastDay=new Date(Nowdate.getYear(),11,31);

return yearLastDay;

}





//当前月

function showmonthCurrent()

{

var Nowdate=new Date();

var Month=Nowdate.getMonth()+1;

Month=(Month<10)?'-0'+Month:'-'+Month;

return Nowdate.getYear()+Month;

}



//本季开始年月

function showquarterFirstMonth()

{

var Nowdate=new Date();

if(Nowdate.getMonth()<3)

return Nowdate.getYear()+'-01';

else if(Nowdate.getMonth()>2 && Nowdate.getMonth()<6)

return Nowdate.getYear()+'-04';

else if(Nowdate.getMonth()>5 && Nowdate.getMonth()<9)

return Nowdate.getYear()+'-07';

else if(Nowdate.getMonth()>8)

return Nowdate.getYear()+'-10';

}



//本季最后年月

function showquarterLastMonth()

{

var Nowdate=new Date();

if(Nowdate.getMonth()<3)

return Nowdate.getYear()+'-03';

else if(Nowdate.getMonth()>2 && Nowdate.getMonth()<6)

return Nowdate.getYear()+'-06';

else if(Nowdate.getMonth()>5 && Nowdate.getMonth()<9)

return Nowdate.getYear()+'-09';

else if(Nowdate.getMonth()>8)

return Nowdate.getYear()+'-12';

}





//本年开始年月

function showyearFirstMonth()

{

var Nowdate=new Date();

return Nowdate.getYear()+'-01';

}



//本年最后年月

function showyearLastMonth()

{

var Nowdate=new Date();

return Nowdate.getYear()+'-12';

}

//格式化日期格式

function Date.prototype.toString(){

return this.getFullYear()+"-"+(this.getMonth()+1)+"-"+this.getDate();

}

// -->

</mce:script>