JavaScript 计算下月,上月,上周,本季

//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'; }