$variables->getSafeVars(array_keys($_REQUEST));
$matrix = array();
if (empty($med_id) || empty($firstIndex) || empty($daysInMonth) || empty($month) || empty($year)) {
    echo json_encode($matrix);
    exit;
}

$day_index = 0;
for ($i = $firstIndex; $i < ($daysInMonth + $firstIndex); $i++) {
    $day_index++;
    $day = get_day_name($i % 7);
    $q = "select `hours` from `hours_matrix` where `med_id`='$med_id' and `day`='$day'";
    $hours = $db->getRecord($q, false);
    if($hours) {
        $exception_date = $day_index . '-' . $month . '-' . $year;
        $q = "select `hours` from `hours_matrix_exceptions` where `med_id`='$med_id' and `exception_date`='$exception_date'";
        $exceptions = $db->getRecord($q, false);
        if($exceptions) {
            $original = json_decode($hours['hours']);
            $exc = json_decode($exceptions['hours']);
            $result['hours'] = array_diff($original, $exc);
            $diff['hours'] = json_encode(array_values($result['hours']));
            $hours = ($diff['hours'] == '[]') ? array('hours' => '["' . t("Ακυρωμένο ωράριο") . '"]') : $diff;
        }
    }
    $matrix[$day_index . '_' . $day] = $hours;

}
echo json_encode($matrix, JSON_UNESCAPED_UNICODE);