ishida83 · December 27, 2021 04:50
diff --git a/Get week number b/Get week number
 Date.prototype.getWeek = function () {
    var onejan = new Date(this.getFullYear(), 0, 1);
    return Math.ceil((((this - onejan) / 86400000) + onejan.getDay() + 1) / 7);
 };

 var myDate = new Date("2001-02-02");
 myDate.getWeek(); //=> 5
	Date.prototype.getWeek = function () {
	var onejan = new Date(this.getFullYear(), 0, 1);
	return Math.ceil((((this - onejan) / 86400000) + onejan.getDay() + 1) / 7);
	};

	var myDate = new Date("2001-02-02");
	myDate.getWeek(); //=> 5