code: function(aDayOfWeek, aPos) {
        var dow = this.dayOfWeek();
  
        if (aPos === 0 && dow === aDayOfWeek) {
          return true;
        }
  
        // get pos
        var day = this.nthWeekDay(aDayOfWeek, aPos);
  
        if (day === this.day) {
          return true;
        }
  
        return false;
      }
docs: Checks if current time is the nth weekday, relative to the current
  month.  Will always return false when rule resolves outside of current
  month.
  
  @param {ICAL.Time.weekDay} aDayOfWeek       Day of week to check
  @param {Number} aPos                        Relative position
  @return {Boolean}                           True, if its the nth weekday