Nodejs Week Calculate getFirstDayOfWeek()

Here you can find the source of getFirstDayOfWeek()

Method Source Code

Date.prototype.getFirstDayOfWeek = function()
{
    "use strict";
    var temp = new Date(this.getTime());
    var distance = (temp.getDay()-1).mod(7);
    return new Date(this.getTime() - (distance * 86400000));
};

Related

  1. getDateOfISOWeek(w, y)
    Date.prototype.getDateOfISOWeek = function (w, y) {
      var simple = new Date(y, 0, 1 + (w - 1) * 7);
      var dow = simple.getDay();
      var ISOweekStart = simple;
      if (dow <= 4) ISOweekStart.setDate(simple.getDate() - simple.getDay() + 1);
      else ISOweekStart.setDate(simple.getDate() + 8 - simple.getDay());
      return ISOweekStart;
    };
    
  2. getDayofWeek()
    var daysOfWeek = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
    Date.prototype.getDayofWeek = function() {
      return daysOfWeek[this.getDay()];
    
  3. getFullWeek()
    Date.prototype.getFullWeek = function(){
        var jan1, w, d = new Date(this);
        d.setDate(d.getDate()+4-(d.getDay()||7));   
        jan1 = new Date(d.getFullYear(),0,1);       
        w = Math.ceil((((d-jan1)/86400000)+1)/7);   
        return {y: d.getFullYear(), w: w };
    };
    Date.prototype.getWeek = function(){ return this.getFullWeek().w; };
    var getWeeksInYear = function(y){ return new Date(y,11,28).getFullWeek().w; };
    ...
    
  4. getRealWeek()
    Date.prototype.getRealWeek = function()
        var monday = this;
        if (monday.getDay() < 1) {
            monday = monday.clone().next().monday();
        return monday.getWeek();
    };
    
  5. getStudyWeek()
    Date.prototype.getStudyWeek = function () {
      var inc = (this.getDay() == 6) ? 1 : 0;
      return this.getWeek() + inc;
    };
    
  6. moveToBeginOfWeek(weekStart)
    Date.prototype.moveToBeginOfWeek = function(weekStart)
        if (this.getDay() != weekStart) {
            this.moveToDayOfWeek(weekStart, -1);
        return this;
    };