Nodejs Week Calculate weekNumber()

Method Source Code

Date.prototype.weekNumber = function() {
   var MaDate = this;
   var mm = MaDate.getMonth(), jj = MaDate.getDate();

   var annee = MaDate.getFullYear();
   var NumSemaine = 0,
   ListeMois = new Array(31,28,31,30,31,30,31,31,30,31,30,31);

   if (annee %4 == 0 && annee %100 !=0 || annee %400 == 0) {ListeMois[1]=29};
   var TotalJour=0;
   for(cpt=0; cpt<mm; cpt++){TotalJour+=ListeMois[cpt];}
   TotalJour+=jj;/*from  ww w.ja  va  2s .  c o  m*/
   DebutAn = new Date(annee,0,1);
   var JourDebutAn;
   JourDebutAn=DebutAn.getDay();
   if(JourDebutAn==0){JourDebutAn=7};

   TotalJour-=8-JourDebutAn;
   NumSemaine = 1;
   NumSemaine+=Math.floor(TotalJour/7);
   if(TotalJour%7!=0){NumSemaine+=1};

   return(NumSemaine);
}

Related

1. subWeeks(value)

   Date.prototype.subWeeks = function(value) {
     this.subDays(value * 7);
     return this;
   };
   

2. toWeekDays()

   Date.prototype.toWeekDays = function () {
     var weekday = this.clone()
     if (!weekday.is().sunday()) {
       weekday.sunday().add(-7).days()
     var week = [weekday.clone()]
     for (var day = 0; day < 6; day++) {
       week.push(weekday.add(1).days().clone())
     return week
   Date.prototype.toNextWeekDays = function () {
     return this.add(7).days().toWeekDays()
   Date.prototype.toPreviousWeekDays = function () {
     return this.add(-7).days().toWeekDays()
   Date.prototype.compare = function (date) {
     var year = this.getYear() - date.getYear()
     if (year > 0)
       return "In " + year + " Years"
     else if (year < 0)
       return -year + " Years Ago"
     else {
       var month = this.getMonth() - date.getMonth()
       if (month > 0)
         return "In " + month + " Months"
       else if (month < 0)
         return -month + " Months Ago"
       else {
         var week = this.getWeekOfYear() - date.getWeekOfYear()
         if (week > 0)
           return "In " + week + " Weeks"
         else if (week < 0)
           return -week + " Weeks Ago"
         else {
           if (this.getDay() - date.getDay() == 0)
             return "Today"
           else
             return this.toString("dddd")
   

3. toWeekEnd(startsFromSunday)

   Date.prototype.toWeekEnd = function (startsFromSunday) {
       var dayOfWeek = this.getDay();
       if (startsFromSunday) {
           return this.addDays(6 - dayOfWeek);
       if (dayOfWeek == 0) {
           dayOfWeek = 7;
       return this.addDays(7 - dayOfWeek);
   ...
   

4. toWeekStart(startsFromSunday)

   Date.prototype.toWeekStart = function (startsFromSunday) {
       var dayOfWeek = this.getDay();
       if (startsFromSunday) {
           return this.addDays(-dayOfWeek);
       if (dayOfWeek == 0) {
           dayOfWeek = 7;
       return this.addDays(1 - dayOfWeek);
   ...
   

5. weekNo()

   var firstMonday = new Date(1970, 0, 5).getTime()
   Date.prototype.weekNo = function() {
     var _date = new Date(this)
     _date.setHours(0,0,0,0)
     _date.setDate(_date.getDate() - (_date.getDay() || 7))
     var weekNo = Math.ceil((((_date - firstMonday) / 86400000) + 1) / 7)
     return weekNo
   Date.prototype.weekNoRelative = function() {
   ...
   

6. weekday()

   Date.prototype.weekday = function()
     var days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
     return days[this.getDay()];