weekfunction.php

  private function getWeek($week, $year) {
    $dto = new DateTime();
    $result["start"] = $dto->setISODate($year, $week, 0)->format("Y-m-d");
    $result["end"] = $dto->setISODate($year, $week, 6)->format("Y-m-d");
    $result["week"] = $week;
    $result["year"] = $year;
    return $result;
  }