JS gets a week, month, next month, a quarter of the start date, the end date and the judgment date of the week

　　/** * Get start date, end date and judgment date of week, month, month, quarter*/ 　　 //formatted Date: YYYY-MM-DDfunctionformatdate (date) {varMyyear =date.getfullyear (); varMymonth = Date.getmonth () +1; varMyweekday =date.getdate (); if(Mymonth < 10) {Mymonth= "0" +Mymonth; }if(Myweekday < 10) {Myweekday= "0" +Myweekday; }return(myyear+ "-" +mymonth + "-" +myweekday); }//get the number of days in a monthfunctionGetmonthdays (parayear,paramonth) {varMonthstartdate =NewDate (Parayear, Paramonth, 1); varMonthenddate =NewDate (parayear, Paramonth + 1, 1); varDays = (monthenddate-monthstartdate)/(1000 * 60 * 60 * 24);returnDays ; }//get the start date for a weekfunctiongetweekstartdate (parayear,paramonth,paraday,paradayofweek) {varWeekstartdate =NewDate (Parayear, Paramonth, Paraday + 1-Paradayofweek); returnformatdate (weekstartdate); }//get the end date of a weekfunctiongetweekenddate (parayear,paramonth,paraday,paradayofweek) {varWeekenddate =NewDate (Parayear, Paramonth, Paraday + (7-Paradayofweek)); returnformatdate (weekenddate); }//get the start date of a monthfunctiongetmonthstartdate (parayear,paramonth) {varMonthstartdate =NewDate (Parayear, Paramonth, 1); returnformatdate (monthstartdate); }//get the end date of a monthfunctiongetmonthenddate (parayear,paramonth) {varMonthenddate =NewDate (Parayear,paramonth, Getmonthdays (Parayear,paramonth)); returnformatdate (monthenddate); }//get start time last monthfunctiongetlastmonthstartdate (parayear, lastmonth) {varLastmonthstartdate =NewDate (Parayear, Lastmonth, 1); returnformatdate (lastmonthstartdate); }//get last month end timefunctiongetlastmonthenddate (Parayear, Lastmonth, lastmonth) {varLastmonthenddate =NewDate (Parayear, Lastmonth, Getmonthdays (Lastmonth)); returnformatdate (lastmonthenddate); }//get the start date for a quarterfunctiongetquarterstartdate (Parayear,paraseason) {Switch(Paraseason) { Case' 1 ':returnparayear+ "-01-01";  Case' 2 ':returnparayear+ "-04-01";  Case' 3 ':returnparayear+ "-07-01";  Case' 4 ':returnparayear+ "-10-01"; }}//Get the end date for a quarterfunctiongetquarterenddate (Parayear,paraseason) {Switch(Paraseason) { Case' 1 ':returnparayear+ "-03-31";  Case' 2 ':returnparayear+ "-06-30";  Case' 3 ':returnparayear+ "-09-30";  Case' 4 ':returnparayear+ "-12-31"; }}//get the start date of a week of a yearfunctionGetbegindateofweek (parayear, weekindex) {varFirstDay =Getfirstweekbegday (parayear); //7*24*3600000 is the time of the week in milliseconds, (the date in JS is accurate to milliseconds) 　  varTime= (weekIndex-1) *7*24*3600000; varBeginday =FirstDay; //Reset the Date object date to timeBeginday.settime (firstday.valueof () +Time ); returnformatdate (beginday);} //get the end date of a week of a yearfunctionGetenddateofweek (parayear, weekindex) {varFirstDay =Getfirstweekbegday (parayear); //7*24*3600000 is the time of the week in milliseconds, (the date in JS is accurate to milliseconds) 　  varTime= (weekIndex-1) *7*24*3600000; varWeektime = 6*24*3600000; varEndday =FirstDay; //Reset the Date object date to timeEndday.settime (firstday.valueof () +weektime+Time ); returnformatdate (endday);} //get date is the week ordinal of a yearfunctionGetweekindex (dateobj) {varFirstDay =Getfirstweekbegday (Dateobj.getfullyear ()); if(Dateobj <firstday) {FirstDay= Getfirstweekbegday (Dateobj.getfullyear ()-1); } d= Math.floor ((dateobj.valueof ()-firstday.valueof ())/86400000); returnMath.floor (D/7) + 1;} //get the first day of a yearfunctionGetfirstweekbegday (year) {varTempdate =NewDate (year, 0, 1); vartemp =Tempdate.getday (); if(Temp = = 1) {returntempdate; } temp= Temp = = 0 7: temp; Tempdate= Tempdate.setdate (Tempdate.getdate () + (8-temp)); return NewDate (tempdate);}

JS gets a week, month, next month, a quarter of the start date, the end date and the judgment date of the week