code: function (d) {
  		"use strict";
  
  		if (typeof d === "number") {
  			d = new Date(d);
  		}
  
  		var monthFirstWeekNumber = this.getWeekNumber(new Date(d.getFullYear(), d.getMonth()));
  		return this.getWeekNumber(d) - monthFirstWeekNumber - 1;
  	}
docs: Return the week number, relative to its month
  
  @param  int|Date d Date or timestamp in milliseconds
  @return int Week number, relative to the month [0-5]