Nodejs Utililty Methods Week Get

Date.prototype.getWeekNumber = function () {
    var d = new Date(+this);
    d.setHours(0, 0, 0, 0);
    d.setDate(d.getDate() + 4 - (d.getDay() || 7));
    return Math.ceil((((d - new Date(d.getFullYear(), 0, 1)) / 8.64e7) + 1) / 7);
};

Date.prototype.getWeekNumber = function () {
  var d = new Date(this);
  d.setHours(0, 0, 0);
  d.setDate(d.getDate() + 4 - (d.getDay() || 7));
  return Math.ceil((((d - new Date(d.getFullYear(), 0, 1)) / 8.64e7) + 1) / 7);
};

Date.prototype.getWeekOfMonth = function () {
  var today = new Date(this.getFullYear(), this.getMonth(), this.getDate());
  var firstOfMonth = new Date(today.getFullYear(), today.getMonth(), 1);
  return Math.ceil((((today - firstOfMonth) / 86400000) + firstOfMonth.getDay() + 1) / 7);
};

Date.prototype.getWeekOfYear = function() {
  var d = new Date(+this);
  d.setHours(0,0,0);
  d.setDate(d.getDate()+4-(d.getDay()||7));
  return Math.ceil((((d-new Date(d.getFullYear(),0,1))/8.64e7))/7);
};

Date.prototype.getWeekOfYear = function () {
    var now = this.getDayOfYear() + (4 - this.getDay());
    var jan1 = new Date(this.getFullYear(), 0, 1);
    var then = (7 - jan1.getDay() + 4);
    document.write(then);
    return String.leftPad(((now - then) / 7) + 1, 2, "0");

Date.prototype.getWeekOfYear = function () {
  var today = new Date(this.getFullYear(), this.getMonth(), this.getDate());
  var firstOfYear = new Date(today.getFullYear(), 0, 1);
  return Math.ceil((((today - firstOfYear) / 86400000) + firstOfYear.getDay() + 1) / 7);
};