diff --git a/admin/anfragen.php b/admin/anfragen.php
index 238d5d5..ac8f9f7 100644
--- a/admin/anfragen.php
+++ b/admin/anfragen.php
@@ -4,6 +4,7 @@ session_start();
 // WICHTIG: Pfade aus /admin heraus korrekt auflösen
 require_once __DIR__ . "/../inc/config.inc.php";
 require_once __DIR__ . "/../inc/functions.inc.php";
+require_once __DIR__ . "/../inc/company_holiday_sync.inc.php";
 
 // Login prüfen
 $user = check_admin_user();
@@ -624,12 +625,12 @@ if(!check_worker()){
 
 					echo "Start: <input class='form-control' name='Starttime[]' type='date' value='" . htmlspecialchars($start, ENT_QUOTES, 'UTF-8') . "'>
 						  Ende: <input class='form-control' name='Endetime[]' type='date' value='" . htmlspecialchars($ende, ENT_QUOTES, 'UTF-8') . "'><br>
-						  Vertretung: <input class='form-control' name='vertretung[]' type='text' value='" . htmlspecialchars($vertretung, ENT_QUOTES, 'UTF-8') . "'>";
+						  Vertretung: <input class='form-control' name='vertretung[]' type='text' required value='" . htmlspecialchars($vertretung, ENT_QUOTES, 'UTF-8') . "'>";
 
-					echo "<br>Vertretung Telefon: <input class='form-control' name='vertretertelefon[]' type='text' value='" . htmlspecialchars($vertretertelefon, ENT_QUOTES, 'UTF-8') . "'>
-						  <br>Vertretung Adresse: <input class='form-control' name='vertreteradresse[]' type='text' value='" . htmlspecialchars($vertreteradresse, ENT_QUOTES, 'UTF-8') . "'>";
+					echo "<br>Vertretung Telefon: <input class='form-control' name='vertretertelefon[]' type='text' required value='" . htmlspecialchars($vertretertelefon, ENT_QUOTES, 'UTF-8') . "'>
+						  <br>Vertretung Adresse: <input class='form-control' name='vertreteradresse[]' type='text' required value='" . htmlspecialchars($vertreteradresse, ENT_QUOTES, 'UTF-8') . "'>";
 
-					echo "<br>Vertretung Webseite: <input class='form-control' name='vertreterurl[]' type='text' value='" . htmlspecialchars($vertreterurl, ENT_QUOTES, 'UTF-8') . "'>";
+					echo "<br>Vertretung Webseite: <input class='form-control' name='vertreterurl[]' type='text' required value='" . htmlspecialchars($vertreterurl, ENT_QUOTES, 'UTF-8') . "'>";
 
 					echo "<input name='urlaubid[]' type='hidden' value='" . $urlaubid . "'><br>";
 				}
@@ -656,40 +657,64 @@ if(!check_worker()){
 		}else if (($_POST["aktion"] ?? '') == "5") {
 			// Termine in DB speichern.
 			$i =0;
-			foreach ($_POST['Starttime'] as $Starttime) { 
-				//echo $datum . "<br>";	
-				if($_POST["Starttime"][$i] != "0000-00-00"){
-					//echo $_POST["urlaubid"][$i] . "<br>";
-					$stmt = $pdo->prepare("
-						INSERT INTO urlaub
-						(urlaubid, vertretung, start, ende, vertretertelefon, vertreteradresse, vertreterurl)
-						VALUES
-						(:urlaubid, :vertretung, :start, :ende, :telefon, :adresse, :url)
-						ON DUPLICATE KEY UPDATE
-							vertretung = VALUES(vertretung),
-							start = VALUES(start),
-							ende = VALUES(ende),
-							vertretertelefon = VALUES(vertretertelefon),
-							vertreteradresse = VALUES(vertreteradresse),
-							vertreterurl = VALUES(vertreterurl)
-					");
+			$pdo->beginTransaction();
+			try {
+				foreach ($_POST['Starttime'] as $Starttime) { 
+					if($_POST["Starttime"][$i] != "0000-00-00"){
+						$vertretung = trim((string)($_POST['vertretung'][$i] ?? ''));
+						$vertretertelefon = trim((string)($_POST['vertretertelefon'][$i] ?? ''));
+						$vertreteradresse = trim((string)($_POST['vertreteradresse'][$i] ?? ''));
+						$vertreterurl = trim((string)($_POST['vertreterurl'][$i] ?? ''));
 
-					$ok = $stmt->execute([
-						':urlaubid'   => (int)$_POST['urlaubid'][$i],  // 0 = INSERT, >0 = UPDATE
-						':vertretung' => $_POST['vertretung'][$i],
-						':start'      => $_POST['Starttime'][$i],
-						':ende'       => $_POST['Endetime'][$i],
-						':telefon'    => $_POST['vertretertelefon'][$i],
-						':adresse'    => $_POST['vertreteradresse'][$i],
-						':url'        => $_POST['vertreterurl'][$i],
-					]);
+						if ($vertretung === '' || $vertretertelefon === '' || $vertreteradresse === '' || $vertreterurl === '') {
+							throw new RuntimeException("Bitte alle Vertreterinformationen fuer jeden Urlaubseintrag vollstaendig ausfuellen.");
+						}
 
-					if (!$ok) {
-						throw new RuntimeException("Fehler beim Eintragen in der Datenbank.");
+						$stmt = $pdo->prepare("
+							INSERT INTO urlaub
+							(urlaubid, vertretung, start, ende, vertretertelefon, vertreteradresse, vertreterurl)
+							VALUES
+							(:urlaubid, :vertretung, :start, :ende, :telefon, :adresse, :url)
+							ON DUPLICATE KEY UPDATE
+								vertretung = VALUES(vertretung),
+								start = VALUES(start),
+								ende = VALUES(ende),
+								vertretertelefon = VALUES(vertretertelefon),
+								vertreteradresse = VALUES(vertreteradresse),
+								vertreterurl = VALUES(vertreterurl)
+						");
+
+						$ok = $stmt->execute([
+							':urlaubid'   => (int)$_POST['urlaubid'][$i],  // 0 = INSERT, >0 = UPDATE
+							':vertretung' => $vertretung,
+							':start'      => $_POST['Starttime'][$i],
+							':ende'       => $_POST['Endetime'][$i],
+							':telefon'    => $vertretertelefon,
+							':adresse'    => $vertreteradresse,
+							':url'        => $vertreterurl,
+						]);
+
+						if (!$ok) {
+							throw new RuntimeException("Fehler beim Eintragen in der Datenbank.");
+						}
+
+						$urlaubId = (int)$_POST['urlaubid'][$i];
+						if ($urlaubId <= 0) {
+							$urlaubId = (int)$pdo->lastInsertId();
+						}
+						if ($urlaubId > 0) {
+							vacationSyncCompanyHolidayFromUrlaub($pdo, $urlaubId, $internUserId);
+						}
 					}
+					$i++;
 				}
-				$i++;
-			}	
+				$pdo->commit();
+			} catch (Throwable $e) {
+				if ($pdo->inTransaction()) {
+					$pdo->rollBack();
+				}
+				throw $e;
+			}
 			echo "Einträge wurden in der Datenbank gespeichert!<br><br>";
 
 		}else if (($_POST["aktion"] ?? '') == "6") {
@@ -2023,10 +2048,10 @@ if(!check_worker()){
 			<script type="text/javascript">
 			
 		function AddneueTermine(){
-			
+		
 			var div = document.getElementById('neuerUrlaub');
-
-			div.innerHTML += "Start: <input name=Starttime[] type=date class='form-control' > Ende: <input name=Endetime[] type=date class='form-control' >Vertretung: <input type=text name=vertretung[] weight=100 class='form-control'> Vertretung Telefon: <input type=text name=vertretertelefon[] weight=100 class='form-control'> Vertretung Adresse: <input type=text name=vertreteradresse[] weight=100 class='form-control'> Vertretung Webseite: <input type=text name=vertreterurl[] weight=100 class='form-control'>  <input name=urlaubid[] type=hidden value='0'>  <br>";
+			
+			div.innerHTML += "Start: <input name=Starttime[] type=date class='form-control' > Ende: <input name=Endetime[] type=date class='form-control' >Vertretung: <input type=text name=vertretung[] weight=100 class='form-control' required> Vertretung Telefon: <input type=text name=vertretertelefon[] weight=100 class='form-control' required> Vertretung Adresse: <input type=text name=vertreteradresse[] weight=100 class='form-control' required> Vertretung Webseite: <input type=text name=vertreterurl[] weight=100 class='form-control' required>  <input name=urlaubid[] type=hidden value='0'>  <br>";
 			//Public: <select name=aktiv[] id='aktiv' required ><option value='1' >Ja</option>	<option value='0'>Nein</option></select>
 			
 			//document.getElementById('neueTermine').innerHTML = div;
diff --git a/admin/impfworkflow.php b/admin/impfworkflow.php
index 1dd21b9..d8db8d8 100644
--- a/admin/impfworkflow.php
+++ b/admin/impfworkflow.php
@@ -405,6 +405,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
                                     SendMailMessageVorlage($pdo, '1', $tid, $mailTemplateId);
                                 }
 
+                                impfWorkflowNotificationProcess($pdo);
                                 $message = count($terminIds) . " Terminanfragen wurden erstellt und versendet.";
                             } catch (Throwable $e) {
                                 if ($pdo->inTransaction()) {
@@ -436,7 +437,11 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             1
         );
         if ($ok) {
+            $notificationEvents = impfWorkflowNotificationProcess($pdo);
             $message = $msg;
+            if (!empty($notificationEvents)) {
+                $message .= ' ' . count($notificationEvents) . " Impfworkflow-Benachrichtigung(en) wurden versendet.";
+            }
         } else {
             $error = $msg;
         }
@@ -481,7 +486,11 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
                     1
                 );
                 if ($ok) {
+                    $notificationEvents = impfWorkflowNotificationProcess($pdo);
                     $message = $msg;
+                    if (!empty($notificationEvents)) {
+                        $message .= ' ' . count($notificationEvents) . " Impfworkflow-Benachrichtigung(en) wurden versendet.";
+                    }
                 } else {
                     $error = $msg;
                 }
@@ -595,6 +604,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $exists = (bool)$stDelete->fetch(PDO::FETCH_ASSOC);
             workflowDeleteWaitlistEntry($pdo, $warteid);
             if ($exists) {
+                impfWorkflowNotificationProcess($pdo);
                 $message = "Wartelisten-Eintrag wurde gelöscht.";
             } else {
                 $error = "Wartelisten-Eintrag nicht gefunden.";
@@ -663,51 +673,67 @@ $eventOverview = [];
 $planWaitCounts = [];
 
 try {
-    $stRules = $pdo->prepare("SELECT r.impfstoff_id, r.dosen_pro_flasche, i.impfname,
-                                     COALESCE((SELECT COUNT(DISTINCT w.userid) FROM warteliste w WHERE w.checked = 1 AND (w.impfstoff = r.impfstoff_id OR w.impfstoff = 0)),0) AS wartende
-                              FROM impfstoff_workflow r
-                              INNER JOIN impfstoff i ON i.impfid = r.impfstoff_id
-                              WHERE (i.aktiv = 1 OR i.aktivwarteliste = 1 OR i.aktivtermin = 1 OR i.aktivgrippe = 1)
-                              ORDER BY i.impfname");
-    $stRules->execute();
-    $rules = $stRules->fetchAll(PDO::FETCH_ASSOC);
+    $needsPlanData = in_array($view, ['teilnehmer', 'event-create'], true);
+    $needsEligibilityData = ($view === 'event-create');
+    $needsPersonSearch = ($view === 'teilnehmer' && $personSearch !== '');
+    $needsWaitRows = ($view === 'warteliste');
+    $needsUpcomingRows = ($view === 'event-teilnehmer');
 
-    $plans = impfGetZeitraumRows($pdo, true);
+    if ($needsPlanData) {
+        $stRules = $pdo->prepare("SELECT r.impfstoff_id, r.dosen_pro_flasche, i.impfname,
+                                         COALESCE((SELECT COUNT(DISTINCT w.userid) FROM warteliste w WHERE w.checked = 1 AND (w.impfstoff = r.impfstoff_id OR w.impfstoff = 0)),0) AS wartende
+                                  FROM impfstoff_workflow r
+                                  INNER JOIN impfstoff i ON i.impfid = r.impfstoff_id
+                                  WHERE (i.aktiv = 1 OR i.aktivwarteliste = 1 OR i.aktivtermin = 1 OR i.aktivgrippe = 1)
+                                  ORDER BY i.impfname");
+        $stRules->execute();
+        $rules = $stRules->fetchAll(PDO::FETCH_ASSOC);
 
-    $planExistsForImpfstoff = [];
-    foreach ($plans as $p) {
-        foreach ($p['impfstoff_id_list'] as $impfstoffId) {
-            $planExistsForImpfstoff[(int)$impfstoffId] = true;
-        }
-    }
+        $plans = impfGetZeitraumRows($pdo, true);
 
-    foreach ($rules as $r) {
-        $iid = (int)$r['impfstoff_id'];
-        $dosen = (int)$r['dosen_pro_flasche'];
-        if ($dosen <= 0 || !isset($planExistsForImpfstoff[$iid])) {
-            continue;
+        $planExistsForImpfstoff = [];
+        foreach ($plans as $p) {
+            foreach ($p['impfstoff_id_list'] as $impfstoffId) {
+                $planExistsForImpfstoff[(int)$impfstoffId] = true;
+            }
         }
 
-        $configuredImpfstoffe[] = $r;
-        $hasEligiblePlan = false;
-        foreach ($plans as $plan) {
-            if (!in_array($iid, $plan['impfstoff_id_list'] ?? [], true)) {
+        foreach ($rules as $r) {
+            $iid = (int)$r['impfstoff_id'];
+            if (!isset($planExistsForImpfstoff[$iid])) {
                 continue;
             }
 
-            $planId = (int)$plan['zeitraum_id'];
-            $planWaitCounts[$iid][$planId] = workflowCountWaitersForPlan($pdo, $iid, $planId);
-            if ($planWaitCounts[$iid][$planId] >= $dosen) {
-                $hasEligiblePlan = true;
+            $configuredImpfstoffe[] = $r;
+            if (!$needsEligibilityData) {
+                continue;
             }
-        }
 
-        if ($hasEligiblePlan) {
-            $eligible[] = $r;
+            $dosen = (int)$r['dosen_pro_flasche'];
+            if ($dosen <= 0) {
+                continue;
+            }
+
+            $hasEligiblePlan = false;
+            foreach ($plans as $plan) {
+                if (!in_array($iid, $plan['impfstoff_id_list'] ?? [], true)) {
+                    continue;
+                }
+
+                $planId = (int)$plan['zeitraum_id'];
+                $planWaitCounts[$iid][$planId] = workflowCountWaitersForPlan($pdo, $iid, $planId);
+                if ($planWaitCounts[$iid][$planId] >= $dosen) {
+                    $hasEligiblePlan = true;
+                }
+            }
+
+            if ($hasEligiblePlan) {
+                $eligible[] = $r;
+            }
         }
     }
 
-    if ($personSearch !== '') {
+    if ($needsPersonSearch) {
         $searchLike = '%' . $personSearch . '%';
         $searchExactId = ctype_digit($personSearch) ? (int)$personSearch : -1;
         $stPersons = $pdo->prepare("SELECT person_id, vorname, nachname, geburtstag, email, tele, ort, plz, strasse
@@ -726,74 +752,78 @@ try {
         $personResults = $stPersons->fetchAll(PDO::FETCH_ASSOC);
     }
 
-    $stWait = $pdo->prepare("SELECT w.warteid, w.userid, w.checked, w.impfstoff, w.impfart, w.impfenzeitraum, w.zeitraum_id, w.letzteimpfung, w.date_created,
-                                    p.vorname, p.nachname, p.geburtstag, p.email, p.tele,
-                                    i.impfname
-                             FROM warteliste w
-                             INNER JOIN persons p ON p.person_id = w.userid
-                             LEFT JOIN impfstoff i ON i.impfid = w.impfstoff
-                             WHERE w.checked IN (0, 1)
-                             ORDER BY w.checked DESC, w.date_created ASC
-                             LIMIT 500");
-    $stWait->execute();
-    $waitRows = $stWait->fetchAll(PDO::FETCH_ASSOC);
+    if ($needsWaitRows) {
+        $stWait = $pdo->prepare("SELECT w.warteid, w.userid, w.checked, w.impfstoff, w.impfart, w.impfenzeitraum, w.zeitraum_id, w.letzteimpfung, w.date_created,
+                                        p.vorname, p.nachname, p.geburtstag, p.email, p.tele,
+                                        i.impfname
+                                 FROM warteliste w
+                                 INNER JOIN persons p ON p.person_id = w.userid
+                                 LEFT JOIN impfstoff i ON i.impfid = w.impfstoff
+                                 WHERE w.checked IN (0, 1)
+                                 ORDER BY w.checked DESC, w.date_created ASC
+                                 LIMIT 500");
+        $stWait->execute();
+        $waitRows = $stWait->fetchAll(PDO::FETCH_ASSOC);
 
-    foreach ($waitRows as &$waitRow) {
-        $waitRow['zeitraum_labels'] = impfGetWartelistenZeitraeumeLabels($pdo, (int)$waitRow['warteid'], false);
-        if (!empty($waitRow['zeitraum_labels'])) {
-            $waitRow['impfenzeitraum'] = implode(' | ', $waitRow['zeitraum_labels']);
+        $waitIds = array_map(static function (array $waitRow): int {
+            return (int)($waitRow['warteid'] ?? 0);
+        }, $waitRows);
+        $waitLabelsById = impfGetWartelistenZeitraeumeLabelsMap($pdo, $waitIds, false);
+
+        foreach ($waitRows as &$waitRow) {
+            $warteid = (int)($waitRow['warteid'] ?? 0);
+            $waitRow['zeitraum_labels'] = $waitLabelsById[$warteid] ?? [];
+            if (!empty($waitRow['zeitraum_labels'])) {
+                $waitRow['impfenzeitraum'] = implode(' | ', $waitRow['zeitraum_labels']);
+            }
         }
-    }
-    unset($waitRow);
-
-    $notificationEvents = impfWorkflowNotificationProcess($pdo);
-    if (!empty($notificationEvents)) {
-        $notificationText = count($notificationEvents) . " Impfworkflow-Benachrichtigung(en) wurden versendet.";
-        $message = ($message === '') ? $notificationText : ($message . ' ' . $notificationText);
+        unset($waitRow);
     }
 
-    $stUpcoming = $pdo->prepare("SELECT ts.timeid, ts.date, ts.start, ts.ende, ts.impfdosen,
-                                        i.impfname, o.anzeigename, o.adresse,
-                                        it.terminid, it.checked, it.behandelt, it.impfart,
-                                        p.vorname, p.nachname, p.geburtstag, p.email, p.tele
-                                 FROM timeslots ts
-                                 INNER JOIN impfstoff i ON i.impfid = ts.impfstoff
-                                 LEFT JOIN impfort o ON o.ortid = ts.impfortid
-                                 LEFT JOIN impftermin it ON it.timeid = ts.timeid
-                                 LEFT JOIN persons p ON p.person_id = it.userid
-                                 WHERE ts.date >= :today
-                                   AND ts.aktiv = 1
-                                 ORDER BY ts.date, ts.start, ts.ende, i.impfname, p.nachname, p.vorname");
-    $stUpcoming->execute(['today' => date('Y-m-d')]);
-    $upcomingRows = $stUpcoming->fetchAll(PDO::FETCH_ASSOC);
+    if ($needsUpcomingRows) {
+        $stUpcoming = $pdo->prepare("SELECT ts.timeid, ts.date, ts.start, ts.ende, ts.impfdosen,
+                                            i.impfname, o.anzeigename, o.adresse,
+                                            it.terminid, it.checked, it.behandelt, it.impfart,
+                                            p.vorname, p.nachname, p.geburtstag, p.email, p.tele
+                                     FROM timeslots ts
+                                     INNER JOIN impfstoff i ON i.impfid = ts.impfstoff
+                                     LEFT JOIN impfort o ON o.ortid = ts.impfortid
+                                     LEFT JOIN impftermin it ON it.timeid = ts.timeid
+                                     LEFT JOIN persons p ON p.person_id = it.userid
+                                     WHERE ts.date >= :today
+                                       AND ts.aktiv = 1
+                                     ORDER BY ts.date, ts.start, ts.ende, i.impfname, p.nachname, p.vorname");
+        $stUpcoming->execute(['today' => date('Y-m-d')]);
+        $upcomingRows = $stUpcoming->fetchAll(PDO::FETCH_ASSOC);
 
-    foreach ($upcomingRows as $row) {
-        $timeid = (int)$row['timeid'];
-        if (!isset($eventOverview[$timeid])) {
-            $eventOverview[$timeid] = [
-                'timeid' => $timeid,
-                'date' => $row['date'],
-                'start' => $row['start'],
-                'ende' => $row['ende'],
-                'impfdosen' => (int)$row['impfdosen'],
-                'impfname' => $row['impfname'],
-                'anzeigename' => $row['anzeigename'],
-                'adresse' => $row['adresse'],
-                'teilnehmer' => [],
-            ];
-        }
-        if (!empty($row['terminid'])) {
-            $eventOverview[$timeid]['teilnehmer'][] = [
-                'terminid' => (int)$row['terminid'],
-                'checked' => (int)($row['checked'] ?? 0),
-                'behandelt' => (int)($row['behandelt'] ?? 0),
-                'impfart' => (int)($row['impfart'] ?? 1),
-                'vorname' => (string)($row['vorname'] ?? ''),
-                'nachname' => (string)($row['nachname'] ?? ''),
-                'geburtstag' => (string)($row['geburtstag'] ?? ''),
-                'email' => (string)($row['email'] ?? ''),
-                'tele' => (string)($row['tele'] ?? ''),
-            ];
+        foreach ($upcomingRows as $row) {
+            $timeid = (int)$row['timeid'];
+            if (!isset($eventOverview[$timeid])) {
+                $eventOverview[$timeid] = [
+                    'timeid' => $timeid,
+                    'date' => $row['date'],
+                    'start' => $row['start'],
+                    'ende' => $row['ende'],
+                    'impfdosen' => (int)$row['impfdosen'],
+                    'impfname' => $row['impfname'],
+                    'anzeigename' => $row['anzeigename'],
+                    'adresse' => $row['adresse'],
+                    'teilnehmer' => [],
+                ];
+            }
+            if (!empty($row['terminid'])) {
+                $eventOverview[$timeid]['teilnehmer'][] = [
+                    'terminid' => (int)$row['terminid'],
+                    'checked' => (int)($row['checked'] ?? 0),
+                    'behandelt' => (int)($row['behandelt'] ?? 0),
+                    'impfart' => (int)($row['impfart'] ?? 1),
+                    'vorname' => (string)($row['vorname'] ?? ''),
+                    'nachname' => (string)($row['nachname'] ?? ''),
+                    'geburtstag' => (string)($row['geburtstag'] ?? ''),
+                    'email' => (string)($row['email'] ?? ''),
+                    'tele' => (string)($row['tele'] ?? ''),
+                ];
+            }
         }
     }
 } catch (Throwable $e) {
@@ -1257,5 +1287,5 @@ try {
 </div>
 
 <?php include __DIR__ . "/templates/footer.inc.php"; ?>
-
-
+
+
diff --git a/inc/company_holiday_sync.inc.php b/inc/company_holiday_sync.inc.php
new file mode 100644
index 0000000..e64b443
--- /dev/null
+++ b/inc/company_holiday_sync.inc.php
@@ -0,0 +1,373 @@
+<?php
+
+if (!function_exists('vacationSyncTableExists')) {
+    function vacationSyncTableExists(PDO $pdo, string $table): bool
+    {
+        $stmt = $pdo->prepare("SHOW TABLES LIKE :table_name");
+        $stmt->execute(['table_name' => $table]);
+        return (bool)$stmt->fetchColumn();
+    }
+}
+
+if (!function_exists('vacationSyncTableHasColumn')) {
+    function vacationSyncTableHasColumn(PDO $pdo, string $table, string $column): bool
+    {
+        $stmt = $pdo->prepare("SHOW COLUMNS FROM `" . $table . "` LIKE :column_name");
+        $stmt->execute(['column_name' => $column]);
+        return (bool)$stmt->fetch(PDO::FETCH_ASSOC);
+    }
+}
+
+if (!function_exists('vacationSyncEnsureSchema')) {
+    function vacationSyncEnsureSchema(PDO $pdo): void
+    {
+        $urlaubExists = vacationSyncTableExists($pdo, 'urlaub');
+        $companyHolidaysExists = vacationSyncTableExists($pdo, 'company_holidays');
+
+        if (!$urlaubExists && !$companyHolidaysExists) {
+            return;
+        }
+
+        if ($urlaubExists && !vacationSyncTableHasColumn($pdo, 'urlaub', 'company_holiday_id')) {
+            $pdo->exec("ALTER TABLE urlaub ADD COLUMN company_holiday_id INT NULL AFTER vertreterurl");
+        }
+
+        if (!$companyHolidaysExists) {
+            return;
+        }
+
+        if (!vacationSyncTableHasColumn($pdo, 'company_holidays', 'urlaub_id')) {
+            $pdo->exec("ALTER TABLE company_holidays ADD COLUMN urlaub_id INT NULL AFTER created_by");
+        }
+
+        if (!vacationSyncTableHasColumn($pdo, 'company_holidays', 'vertretung')) {
+            $pdo->exec("ALTER TABLE company_holidays ADD COLUMN vertretung VARCHAR(255) NOT NULL DEFAULT '' AFTER description");
+        }
+
+        if (!vacationSyncTableHasColumn($pdo, 'company_holidays', 'vertretertelefon')) {
+            $pdo->exec("ALTER TABLE company_holidays ADD COLUMN vertretertelefon VARCHAR(255) NOT NULL DEFAULT '' AFTER vertretung");
+        }
+
+        if (!vacationSyncTableHasColumn($pdo, 'company_holidays', 'vertreteradresse')) {
+            $pdo->exec("ALTER TABLE company_holidays ADD COLUMN vertreteradresse VARCHAR(1000) NOT NULL DEFAULT '' AFTER vertretertelefon");
+        }
+
+        if (!vacationSyncTableHasColumn($pdo, 'company_holidays', 'vertreterurl')) {
+            $pdo->exec("ALTER TABLE company_holidays ADD COLUMN vertreterurl VARCHAR(255) NOT NULL DEFAULT '' AFTER vertreteradresse");
+        }
+    }
+}
+
+if (!function_exists('vacationSyncFindCompanyHolidayIdForUrlaub')) {
+    function vacationSyncFindCompanyHolidayIdForUrlaub(PDO $pdo, int $urlaubId): int
+    {
+        if ($urlaubId <= 0) {
+            return 0;
+        }
+
+        if (!vacationSyncTableExists($pdo, 'urlaub') || !vacationSyncTableExists($pdo, 'company_holidays')) {
+            return 0;
+        }
+
+        vacationSyncEnsureSchema($pdo);
+
+        $stmt = $pdo->prepare("SELECT company_holiday_id FROM urlaub WHERE urlaubid = :urlaub_id LIMIT 1");
+        $stmt->execute(['urlaub_id' => $urlaubId]);
+        $linkedId = (int)($stmt->fetchColumn() ?: 0);
+        if ($linkedId > 0) {
+            return $linkedId;
+        }
+
+        $stmt = $pdo->prepare("SELECT id FROM company_holidays WHERE urlaub_id = :urlaub_id LIMIT 1");
+        $stmt->execute(['urlaub_id' => $urlaubId]);
+        $linkedId = (int)($stmt->fetchColumn() ?: 0);
+        if ($linkedId > 0) {
+            return $linkedId;
+        }
+
+        $stmt = $pdo->prepare("SELECT start, ende FROM urlaub WHERE urlaubid = :urlaub_id LIMIT 1");
+        $stmt->execute(['urlaub_id' => $urlaubId]);
+        $urlaub = $stmt->fetch(PDO::FETCH_ASSOC);
+        if (!$urlaub) {
+            return 0;
+        }
+
+        $stmt = $pdo->prepare("
+            SELECT id
+            FROM company_holidays
+            WHERE start_date = :start_date
+              AND end_date = :end_date
+            ORDER BY id ASC
+            LIMIT 1
+        ");
+        $stmt->execute([
+            'start_date' => $urlaub['start'],
+            'end_date' => $urlaub['ende'],
+        ]);
+        return (int)($stmt->fetchColumn() ?: 0);
+    }
+}
+
+if (!function_exists('vacationSyncFindUrlaubIdForCompanyHoliday')) {
+    function vacationSyncFindUrlaubIdForCompanyHoliday(PDO $pdo, int $companyHolidayId): int
+    {
+        if ($companyHolidayId <= 0) {
+            return 0;
+        }
+
+        if (!vacationSyncTableExists($pdo, 'urlaub') || !vacationSyncTableExists($pdo, 'company_holidays')) {
+            return 0;
+        }
+
+        vacationSyncEnsureSchema($pdo);
+
+        $stmt = $pdo->prepare("SELECT urlaub_id FROM company_holidays WHERE id = :company_holiday_id LIMIT 1");
+        $stmt->execute(['company_holiday_id' => $companyHolidayId]);
+        $linkedId = (int)($stmt->fetchColumn() ?: 0);
+        if ($linkedId > 0) {
+            return $linkedId;
+        }
+
+        $stmt = $pdo->prepare("SELECT urlaubid FROM urlaub WHERE company_holiday_id = :company_holiday_id LIMIT 1");
+        $stmt->execute(['company_holiday_id' => $companyHolidayId]);
+        $linkedId = (int)($stmt->fetchColumn() ?: 0);
+        if ($linkedId > 0) {
+            return $linkedId;
+        }
+
+        $stmt = $pdo->prepare("SELECT start_date, end_date FROM company_holidays WHERE id = :company_holiday_id LIMIT 1");
+        $stmt->execute(['company_holiday_id' => $companyHolidayId]);
+        $holiday = $stmt->fetch(PDO::FETCH_ASSOC);
+        if (!$holiday) {
+            return 0;
+        }
+
+        $stmt = $pdo->prepare("
+            SELECT urlaubid
+            FROM urlaub
+            WHERE start = :start_date
+              AND ende = :end_date
+            ORDER BY urlaubid ASC
+            LIMIT 1
+        ");
+        $stmt->execute([
+            'start_date' => $holiday['start_date'],
+            'end_date' => $holiday['end_date'],
+        ]);
+        return (int)($stmt->fetchColumn() ?: 0);
+    }
+}
+
+if (!function_exists('vacationSyncCompanyHolidayFromUrlaub')) {
+    function vacationSyncCompanyHolidayFromUrlaub(PDO $pdo, int $urlaubId, ?int $createdBy = null): int
+    {
+        if ($urlaubId <= 0) {
+            return 0;
+        }
+
+        if (!vacationSyncTableExists($pdo, 'urlaub') || !vacationSyncTableExists($pdo, 'company_holidays')) {
+            return 0;
+        }
+
+        vacationSyncEnsureSchema($pdo);
+
+        $stmtUrlaub = $pdo->prepare("
+            SELECT urlaubid, start, ende, vertretung, vertretertelefon, vertreteradresse, vertreterurl, company_holiday_id
+            FROM urlaub
+            WHERE urlaubid = :urlaub_id
+            LIMIT 1
+        ");
+        $stmtUrlaub->execute(['urlaub_id' => $urlaubId]);
+        $urlaub = $stmtUrlaub->fetch(PDO::FETCH_ASSOC);
+        if (!$urlaub) {
+            return 0;
+        }
+
+        $companyHolidayId = (int)($urlaub['company_holiday_id'] ?? 0);
+        if ($companyHolidayId <= 0) {
+            $companyHolidayId = vacationSyncFindCompanyHolidayIdForUrlaub($pdo, $urlaubId);
+        }
+
+        $description = 'Betriebsurlaub';
+        if ($companyHolidayId > 0) {
+            $stmtExisting = $pdo->prepare("SELECT description FROM company_holidays WHERE id = :company_holiday_id LIMIT 1");
+            $stmtExisting->execute(['company_holiday_id' => $companyHolidayId]);
+            $existingDescription = $stmtExisting->fetchColumn();
+            if ($existingDescription !== false && trim((string)$existingDescription) !== '') {
+                $description = (string)$existingDescription;
+            }
+        }
+
+        if ($companyHolidayId > 0) {
+            $stmtUpdate = $pdo->prepare("
+                UPDATE company_holidays
+                SET start_date = :start_date,
+                    end_date = :end_date,
+                    vertretung = :vertretung,
+                    vertretertelefon = :vertretertelefon,
+                    vertreteradresse = :vertreteradresse,
+                    vertreterurl = :vertreterurl,
+                    urlaub_id = :urlaub_id
+                WHERE id = :company_holiday_id
+            ");
+            $stmtUpdate->execute([
+                'start_date' => $urlaub['start'],
+                'end_date' => $urlaub['ende'],
+                'vertretung' => (string)$urlaub['vertretung'],
+                'vertretertelefon' => (string)$urlaub['vertretertelefon'],
+                'vertreteradresse' => (string)$urlaub['vertreteradresse'],
+                'vertreterurl' => (string)$urlaub['vertreterurl'],
+                'urlaub_id' => $urlaubId,
+                'company_holiday_id' => $companyHolidayId,
+            ]);
+        } else {
+            $stmtInsert = $pdo->prepare("
+                INSERT INTO company_holidays (
+                    start_date, end_date, description, vertretung, vertretertelefon, vertreteradresse, vertreterurl, created_by, urlaub_id
+                )
+                VALUES (
+                    :start_date, :end_date, :description, :vertretung, :vertretertelefon, :vertreteradresse, :vertreterurl, :created_by, :urlaub_id
+                )
+            ");
+            $stmtInsert->execute([
+                'start_date' => $urlaub['start'],
+                'end_date' => $urlaub['ende'],
+                'description' => $description,
+                'vertretung' => (string)$urlaub['vertretung'],
+                'vertretertelefon' => (string)$urlaub['vertretertelefon'],
+                'vertreteradresse' => (string)$urlaub['vertreteradresse'],
+                'vertreterurl' => (string)$urlaub['vertreterurl'],
+                'created_by' => $createdBy,
+                'urlaub_id' => $urlaubId,
+            ]);
+            $companyHolidayId = (int)$pdo->lastInsertId();
+        }
+
+        if ($companyHolidayId > 0) {
+            $stmtLink = $pdo->prepare("UPDATE urlaub SET company_holiday_id = :company_holiday_id WHERE urlaubid = :urlaub_id");
+            $stmtLink->execute([
+                'company_holiday_id' => $companyHolidayId,
+                'urlaub_id' => $urlaubId,
+            ]);
+        }
+
+        return $companyHolidayId;
+    }
+}
+
+if (!function_exists('vacationSyncUrlaubFromCompanyHoliday')) {
+    function vacationSyncUrlaubFromCompanyHoliday(PDO $pdo, int $companyHolidayId): int
+    {
+        if ($companyHolidayId <= 0) {
+            return 0;
+        }
+
+        if (!vacationSyncTableExists($pdo, 'company_holidays') || !vacationSyncTableExists($pdo, 'urlaub')) {
+            return 0;
+        }
+
+        vacationSyncEnsureSchema($pdo);
+
+        $stmtHoliday = $pdo->prepare("
+            SELECT id, start_date, end_date, vertretung, vertretertelefon, vertreteradresse, vertreterurl, urlaub_id
+            FROM company_holidays
+            WHERE id = :company_holiday_id
+            LIMIT 1
+        ");
+        $stmtHoliday->execute(['company_holiday_id' => $companyHolidayId]);
+        $holiday = $stmtHoliday->fetch(PDO::FETCH_ASSOC);
+        if (!$holiday) {
+            return 0;
+        }
+
+        $urlaubId = (int)($holiday['urlaub_id'] ?? 0);
+        if ($urlaubId <= 0) {
+            $urlaubId = vacationSyncFindUrlaubIdForCompanyHoliday($pdo, $companyHolidayId);
+        }
+
+        if ($urlaubId > 0) {
+            $stmtUpdate = $pdo->prepare("
+                UPDATE urlaub
+                SET start = :start_date,
+                    ende = :end_date,
+                    vertretung = :vertretung,
+                    vertretertelefon = :vertretertelefon,
+                    vertreteradresse = :vertreteradresse,
+                    vertreterurl = :vertreterurl,
+                    company_holiday_id = :company_holiday_id
+                WHERE urlaubid = :urlaub_id
+            ");
+            $stmtUpdate->execute([
+                'start_date' => $holiday['start_date'],
+                'end_date' => $holiday['end_date'],
+                'vertretung' => (string)$holiday['vertretung'],
+                'vertretertelefon' => (string)$holiday['vertretertelefon'],
+                'vertreteradresse' => (string)$holiday['vertreteradresse'],
+                'vertreterurl' => (string)$holiday['vertreterurl'],
+                'company_holiday_id' => $companyHolidayId,
+                'urlaub_id' => $urlaubId,
+            ]);
+        } else {
+            $stmtInsert = $pdo->prepare("
+                INSERT INTO urlaub
+                    (vertretung, start, ende, vertretertelefon, vertreteradresse, vertreterurl, company_holiday_id)
+                VALUES
+                    (:vertretung, :start_date, :end_date, :vertretertelefon, :vertreteradresse, :vertreterurl, :company_holiday_id)
+            ");
+            $stmtInsert->execute([
+                'vertretung' => (string)$holiday['vertretung'],
+                'start_date' => $holiday['start_date'],
+                'end_date' => $holiday['end_date'],
+                'vertretertelefon' => (string)$holiday['vertretertelefon'],
+                'vertreteradresse' => (string)$holiday['vertreteradresse'],
+                'vertreterurl' => (string)$holiday['vertreterurl'],
+                'company_holiday_id' => $companyHolidayId,
+            ]);
+            $urlaubId = (int)$pdo->lastInsertId();
+        }
+
+        if ($urlaubId > 0) {
+            $stmtLink = $pdo->prepare("UPDATE company_holidays SET urlaub_id = :urlaub_id WHERE id = :company_holiday_id");
+            $stmtLink->execute([
+                'urlaub_id' => $urlaubId,
+                'company_holiday_id' => $companyHolidayId,
+            ]);
+        }
+
+        return $urlaubId;
+    }
+}
+
+if (!function_exists('vacationSyncDeleteCompanyHolidayByUrlaub')) {
+    function vacationSyncDeleteCompanyHolidayByUrlaub(PDO $pdo, int $urlaubId): void
+    {
+        if (!vacationSyncTableExists($pdo, 'urlaub') || !vacationSyncTableExists($pdo, 'company_holidays')) {
+            return;
+        }
+
+        $companyHolidayId = vacationSyncFindCompanyHolidayIdForUrlaub($pdo, $urlaubId);
+        if ($companyHolidayId <= 0) {
+            return;
+        }
+
+        $stmt = $pdo->prepare("DELETE FROM company_holidays WHERE id = :company_holiday_id");
+        $stmt->execute(['company_holiday_id' => $companyHolidayId]);
+    }
+}
+
+if (!function_exists('vacationSyncDeleteUrlaubByCompanyHoliday')) {
+    function vacationSyncDeleteUrlaubByCompanyHoliday(PDO $pdo, int $companyHolidayId): void
+    {
+        if (!vacationSyncTableExists($pdo, 'urlaub') || !vacationSyncTableExists($pdo, 'company_holidays')) {
+            return;
+        }
+
+        $urlaubId = vacationSyncFindUrlaubIdForCompanyHoliday($pdo, $companyHolidayId);
+        if ($urlaubId <= 0) {
+            return;
+        }
+
+        $stmt = $pdo->prepare("DELETE FROM urlaub WHERE urlaubid = :urlaub_id");
+        $stmt->execute(['urlaub_id' => $urlaubId]);
+    }
+}
diff --git a/inc/functions.impfen.inc.php b/inc/functions.impfen.inc.php
index 6a83e65..85d5672 100644
--- a/inc/functions.impfen.inc.php
+++ b/inc/functions.impfen.inc.php
@@ -550,6 +550,100 @@ if (!function_exists('impfGetWartelistenZeitraeumeLabels')) {
     }
 }
 
+if (!function_exists('impfGetWartelistenZeitraeumeLabelsMap')) {
+    function impfGetWartelistenZeitraeumeLabelsMap(PDO $pdo, array $warteids, bool $onlyActive = false): array
+    {
+        $warteids = array_values(array_unique(array_filter(array_map('intval', $warteids), static function (int $warteid): bool {
+            return $warteid > 0;
+        })));
+
+        if (empty($warteids) || !impfTableExists($pdo, 'warteliste_zeitraum')) {
+            return [];
+        }
+
+        $result = [];
+        foreach ($warteids as $warteid) {
+            $result[$warteid] = [];
+        }
+
+        $placeholders = [];
+        $params = [];
+        foreach ($warteids as $index => $warteid) {
+            $key = 'wid' . $index;
+            $placeholders[] = ':' . $key;
+            $params[$key] = $warteid;
+        }
+        $inList = implode(', ', $placeholders);
+
+        $sql = "SELECT wz.warteid, z.zeitraum_id, z.bezeichnung, z.wochentag, z.start, z.ende, z.impfortid, z.aktiv, z.created_at,
+                       o.anzeigename, o.adresse
+                FROM warteliste_zeitraum wz
+                INNER JOIN impf_zeitraum z ON z.zeitraum_id = wz.zeitraum_id
+                LEFT JOIN impfort o ON o.ortid = z.impfortid
+                WHERE wz.warteid IN (" . $inList . ")";
+        if ($onlyActive) {
+            $sql .= " AND z.aktiv = 1";
+        }
+        $sql .= " ORDER BY wz.warteid, z.wochentag, z.start, z.ende, z.bezeichnung, z.zeitraum_id";
+
+        $st = $pdo->prepare($sql);
+        $st->execute($params);
+        $rows = $st->fetchAll(PDO::FETCH_ASSOC);
+
+        foreach ($rows as $row) {
+            $warteid = (int)($row['warteid'] ?? 0);
+            if ($warteid <= 0) {
+                continue;
+            }
+            $row['label'] = impfZeitraumLabel($row);
+            $result[$warteid][] = (string)$row['label'];
+        }
+
+        $missing = array_values(array_filter($warteids, static function (int $warteid) use ($result): bool {
+            return empty($result[$warteid]);
+        }));
+
+        if (empty($missing)) {
+            return $result;
+        }
+
+        $fallbackPlaceholders = [];
+        $fallbackParams = [];
+        foreach ($missing as $index => $warteid) {
+            $key = 'f_wid' . $index;
+            $fallbackPlaceholders[] = ':' . $key;
+            $fallbackParams[$key] = $warteid;
+        }
+        $fallbackInList = implode(', ', $fallbackPlaceholders);
+
+        $fallbackSql = "SELECT w.warteid, w.zeitraum_id, z.bezeichnung, z.wochentag, z.start, z.ende, z.impfortid, z.aktiv, z.created_at,
+                               o.anzeigename, o.adresse
+                        FROM warteliste w
+                        LEFT JOIN impf_zeitraum z ON z.zeitraum_id = w.zeitraum_id
+                        LEFT JOIN impfort o ON o.ortid = z.impfortid
+                        WHERE w.warteid IN (" . $fallbackInList . ")
+                          AND w.zeitraum_id IS NOT NULL";
+        if ($onlyActive) {
+            $fallbackSql .= " AND z.aktiv = 1";
+        }
+
+        $stFallback = $pdo->prepare($fallbackSql);
+        $stFallback->execute($fallbackParams);
+        $fallbackRows = $stFallback->fetchAll(PDO::FETCH_ASSOC);
+
+        foreach ($fallbackRows as $row) {
+            $warteid = (int)($row['warteid'] ?? 0);
+            if ($warteid <= 0) {
+                continue;
+            }
+            $row['label'] = impfZeitraumLabel($row);
+            $result[$warteid] = [(string)$row['label']];
+        }
+
+        return $result;
+    }
+}
+
 if (!function_exists('impfSetWartelistenZeitraeume')) {
     function impfSetWartelistenZeitraeume(PDO $pdo, int $warteid, $zeitraumIds): void
     {
diff --git a/zeiterfassung/api/vacations.php b/zeiterfassung/api/vacations.php
index a5022ce..021ebdf 100644
--- a/zeiterfassung/api/vacations.php
+++ b/zeiterfassung/api/vacations.php
@@ -1,197 +1,191 @@
-<?php
-// API: returns JSON events for FullCalendar
-session_start();
-require_once(__DIR__ . '/../inc/config.inc.php');
-require_once(__DIR__ . '/../inc/functions.inc.php');
-
-// Enable full error reporting for API debugging
-ini_set('display_errors', '1');
-ini_set('display_startup_errors', '1');
-error_reporting(E_ALL);
-
-$user = check_user();
-$isAdmin = is_admin_user();
-
-$start = $_GET['start'] ?? null; // expected ISO date
-$end = $_GET['end'] ?? null;
-$onlyApproved = isset($_GET['only_approved']) && ($_GET['only_approved'] == '1' || $_GET['only_approved'] === 'true');
-// public allows non-admin users to request all *approved* vacations (team view)
-$public = isset($_GET['public']) && ($_GET['public'] == '1' || $_GET['public'] === 'true');
-// include_rejected if set to 1 will return rejected entries; default behavior: do not return rejected for regular users
-$includeRejected = isset($_GET['include_rejected']) && ($_GET['include_rejected'] == '1' || $_GET['include_rejected'] === 'true');
-// only_personal forces the API to return only the current user's vacations (useful even if the user is admin)
-$onlyPersonal = isset($_GET['only_personal']) && ($_GET['only_personal'] == '1' || $_GET['only_personal'] === 'true');
-// public_all when used with public=1 returns all non-rejected team vacations (approved + beantragt)
-$publicAll = isset($_GET['public_all']) && ($_GET['public_all'] == '1' || $_GET['public_all'] === 'true');
-
-if (!$start || !$end) {
-    http_response_code(400);
-    echo json_encode(['error' => 'start and end required']);
-    exit;
-}
-
-$events = [];
-try {
-$branch = 'unknown';
-$debugMode = isset($_GET['debug']) && ($_GET['debug'] == '1' || $_GET['debug'] === 'true');
-
-// Vacations: support a personal-only mode, admin mode, and public/team mode
-if ($onlyPersonal) {
-    $branch = 'onlyPersonal';
-    if ($onlyApproved) {
-        $branch = 'onlyPersonal_onlyApproved';
-        $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
-        $stmt->execute([$_SESSION['userid'], $end, $start]);
-    } else {
-        if ($includeRejected) {
-            $branch = 'onlyPersonal_includeRejected';
-            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
-            $stmt->execute([$_SESSION['userid'], $end, $start]);
-        } else {
-            $branch = 'onlyPersonal_excludeRejected';
-            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) != 'abgelehnt') ORDER BY v.start_date");
-            $stmt->execute([$_SESSION['userid'], $end, $start]);
-        }
-    }
-} elseif ($isAdmin) {
-    $branch = 'admin';
-    if ($onlyApproved) {
-        $branch = 'admin_onlyApproved';
-        $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
-        $stmt->execute([$end, $start]);
-    } else {
-        // By default admins see genehmigt + beantragt; include_rejected=1 can override
-        if ($includeRejected) {
-            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
-            $stmt->execute([$end, $start]);
-        } else {
-            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) IN ('genehmigt','beantragt')) ORDER BY v.start_date");
-            $stmt->execute([$end, $start]);
-        }
-    }
-} else {
-    $branch = 'public_or_regular';
-    if ($public && $onlyApproved) {
-        $branch = 'public_onlyApproved';
-        // public team view: show all approved vacations (read-only)
-        $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
-        $stmt->execute([$end, $start]);
-    } elseif ($public && $publicAll) {
-        $branch = 'public_publicAll';
-        // public team view: explicitly show only approved (genehmigt) and pending (beantragt) vacations
-        $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) IN ('genehmigt','beantragt')) ORDER BY v.start_date");
-        $stmt->execute([$end, $start]);
-    } else {
-        if ($onlyApproved) {
-            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
-            $stmt->execute([$_SESSION['userid'], $end, $start]);
-        } else {
-            // By default exclude rejected ('abgelehnt') for regular users; include if include_rejected=1
-            if ($includeRejected) {
-                $branch = 'regular_includeRejected';
-                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
-                $stmt->execute([$_SESSION['userid'], $end, $start]);
-            } else {
-                $branch = 'regular_excludeRejected';
-                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) != 'abgelehnt') ORDER BY v.start_date");
-                $stmt->execute([$_SESSION['userid'], $end, $start]);
-            }
-        }
-    }
-}
-
-try {
-    $vacations = $stmt->fetchAll();
-
-    // If debug mode is enabled, prepare meta information
-    if ($debugMode) {
-        $rawStatuses = array_map(function($r){ return $r['status'] ?? null; }, $vacations);
-        $meta = [
-            'branch' => $branch,
-            'count' => count($vacations),
-            'raw_statuses' => $rawStatuses
-        ];
-    }
-
-    foreach ($vacations as $v) {
-        // Normalize status: collapse whitespace (including NBSP), trim, lowercase
-        if (isset($v['status'])) {
-            $normalized = preg_replace('/\s+/u', ' ', $v['status']);
-            $status = mb_strtolower(trim($normalized));
-        } else {
-            $status = '';
-        }
-        // Defensive filter: do not expose rejected ('abgelehnt') entries to non-admins
-        if (!$isAdmin && !$includeRejected && mb_stripos($status, 'abgelehnt') !== false) {
-            continue;
-        }
-        $isApproved = (mb_stripos($status, 'genehmigt') !== false);
-        if ($isAdmin) {
-            $title = $v['vorname'] . ' ' . $v['nachname'] . ' (' . ($v['status'] ?? 'beantragt') . ')';
-        } else {
-            $title = $isApproved ? 'Urlaub' : 'Urlaubsantrag';
-        }
-        // Safely compute end date; fallback to start_date if invalid
-        try {
-            $endInclusive = (new DateTime($v['end_date']))->modify('+1 day')->format('Y-m-d');
-        } catch (Exception $e) {
-            $endInclusive = $v['start_date'];
-        }
-        $events[] = [
-            'id' => 'vac_' . $v['id'],
-            'title' => $title,
-            'start' => $v['start_date'],
-            'end' => $endInclusive,
-            'allDay' => true,
-            'color' => ($isApproved) ? '#28a745' : '#ffc107',
-            'extendedProps' => [
-                'type' => 'user',
-                'user_id' => $v['user_id'],
-                'status' => $v['status'],
-                'comment' => $v['comment_user'] ?? ''
-            ]
-        ];
-    }
-} catch (Exception $ex) {
-    header('Content-Type: application/json; charset=utf-8');
-    $payload = ['error' => $ex->getMessage(), 'branch' => $branch, 'trace' => $ex->getTraceAsString()];
-    echo json_encode($payload);
-    exit;
-}
-
-} catch (Exception $ex) {
-    header('Content-Type: application/json; charset=utf-8');
-    $payload = ['error' => $ex->getMessage(), 'branch' => $branch, 'trace' => $ex->getTraceAsString()];
-    echo json_encode($payload);
-    exit;
-}
-
-// Company holidays (visible to all)
-$stmt = $pdo->prepare("SELECT * FROM company_holidays WHERE start_date <= ? AND end_date >= ? ORDER BY start_date");
-$stmt->execute([$end, $start]);
-$holidays = $stmt->fetchAll();
-
-foreach ($holidays as $h) {
-    $endInclusive = (new DateTime($h['end_date']))->modify('+1 day')->format('Y-m-d');
-    $events[] = [
-        'id' => 'com_' . $h['id'],
-        'title' => $h['description'] ?: 'Betriebsurlaub',
-        'start' => $h['start_date'],
-        'end' => $endInclusive,
-        'allDay' => true,
-        'color' => '#007bff',
-        'extendedProps' => [
-            'type' => 'company',
-            'description' => $h['description']
-        ]
-    ];
-}
-
-header('Content-Type: application/json; charset=utf-8');
-if ($debugMode) {
-    echo json_encode(['events' => $events, 'meta' => $meta]);
-} else {
-    echo json_encode($events);
-}
-
-?>
+<?php
+session_start();
+require_once(__DIR__ . '/../inc/config.inc.php');
+require_once(__DIR__ . '/../inc/functions.inc.php');
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+error_reporting(E_ALL);
+
+$user = check_user();
+$isAdmin = is_admin_user();
+
+$start = $_GET['start'] ?? null;
+$end = $_GET['end'] ?? null;
+$onlyApproved = isset($_GET['only_approved']) && ($_GET['only_approved'] == '1' || $_GET['only_approved'] === 'true');
+$public = isset($_GET['public']) && ($_GET['public'] == '1' || $_GET['public'] === 'true');
+$includeRejected = isset($_GET['include_rejected']) && ($_GET['include_rejected'] == '1' || $_GET['include_rejected'] === 'true');
+$onlyPersonal = isset($_GET['only_personal']) && ($_GET['only_personal'] == '1' || $_GET['only_personal'] === 'true');
+$publicAll = isset($_GET['public_all']) && ($_GET['public_all'] == '1' || $_GET['public_all'] === 'true');
+
+if (!$start || !$end) {
+    http_response_code(400);
+    echo json_encode(['error' => 'start and end required']);
+    exit;
+}
+
+$events = [];
+try {
+    $branch = 'unknown';
+    $debugMode = isset($_GET['debug']) && ($_GET['debug'] == '1' || $_GET['debug'] === 'true');
+    $showEmployeeNames = $isAdmin || $public;
+
+    if ($onlyPersonal) {
+        $branch = 'onlyPersonal';
+        if ($onlyApproved) {
+            $branch = 'onlyPersonal_onlyApproved';
+            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
+            $stmt->execute([$_SESSION['userid'], $end, $start]);
+        } else {
+            if ($includeRejected) {
+                $branch = 'onlyPersonal_includeRejected';
+                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
+                $stmt->execute([$_SESSION['userid'], $end, $start]);
+            } else {
+                $branch = 'onlyPersonal_excludeRejected';
+                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) != 'abgelehnt') ORDER BY v.start_date");
+                $stmt->execute([$_SESSION['userid'], $end, $start]);
+            }
+        }
+    } elseif ($isAdmin) {
+        $branch = 'admin';
+        if ($onlyApproved) {
+            $branch = 'admin_onlyApproved';
+            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
+            $stmt->execute([$end, $start]);
+        } else {
+            if ($includeRejected) {
+                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
+                $stmt->execute([$end, $start]);
+            } else {
+                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) IN ('genehmigt','beantragt')) ORDER BY v.start_date");
+                $stmt->execute([$end, $start]);
+            }
+        }
+    } else {
+        $branch = 'public_or_regular';
+        if ($public && $onlyApproved) {
+            $branch = 'public_onlyApproved';
+            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
+            $stmt->execute([$end, $start]);
+        } elseif ($public && $publicAll) {
+            $branch = 'public_publicAll';
+            $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) IN ('genehmigt','beantragt')) ORDER BY v.start_date");
+            $stmt->execute([$end, $start]);
+        } else {
+            if ($onlyApproved) {
+                $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND LOWER(TRIM(v.status)) = 'genehmigt' ORDER BY v.start_date");
+                $stmt->execute([$_SESSION['userid'], $end, $start]);
+            } else {
+                if ($includeRejected) {
+                    $branch = 'regular_includeRejected';
+                    $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? ORDER BY v.start_date");
+                    $stmt->execute([$_SESSION['userid'], $end, $start]);
+                } else {
+                    $branch = 'regular_excludeRejected';
+                    $stmt = $pdo->prepare("SELECT v.*, u.vorname, u.nachname FROM vacations v JOIN users u ON v.user_id = u.id WHERE v.user_id = ? AND v.start_date <= ? AND v.end_date >= ? AND (v.status IS NULL OR LOWER(TRIM(v.status)) != 'abgelehnt') ORDER BY v.start_date");
+                    $stmt->execute([$_SESSION['userid'], $end, $start]);
+                }
+            }
+        }
+    }
+
+    try {
+        $vacations = $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+        if ($debugMode) {
+            $rawStatuses = array_map(function($r){ return $r['status'] ?? null; }, $vacations);
+            $meta = [
+                'branch' => $branch,
+                'count' => count($vacations),
+                'raw_statuses' => $rawStatuses
+            ];
+        }
+
+        foreach ($vacations as $v) {
+            if (isset($v['status'])) {
+                $normalized = preg_replace('/\s+/u', ' ', $v['status']);
+                $status = mb_strtolower(trim($normalized));
+            } else {
+                $status = '';
+            }
+
+            if (!$isAdmin && !$includeRejected && mb_stripos($status, 'abgelehnt') !== false) {
+                continue;
+            }
+
+            $isApproved = (mb_stripos($status, 'genehmigt') !== false);
+            $employeeName = trim(($v['vorname'] ?? '') . ' ' . ($v['nachname'] ?? ''));
+            if ($showEmployeeNames && $employeeName !== '') {
+                $title = $employeeName;
+                if ($v['status'] !== null && $v['status'] !== '') {
+                    $title .= ' (' . $v['status'] . ')';
+                }
+            } elseif ($isApproved) {
+                $title = 'Urlaub';
+            } else {
+                $title = 'Urlaubsantrag';
+            }
+
+            try {
+                $endInclusive = (new DateTime($v['end_date']))->modify('+1 day')->format('Y-m-d');
+            } catch (Exception $e) {
+                $endInclusive = $v['start_date'];
+            }
+
+            $events[] = [
+                'id' => 'vac_' . $v['id'],
+                'title' => $title,
+                'start' => $v['start_date'],
+                'end' => $endInclusive,
+                'allDay' => true,
+                'color' => ($isApproved) ? '#28a745' : '#ffc107',
+                'extendedProps' => [
+                    'type' => 'user',
+                    'user_id' => $v['user_id'],
+                    'employee_name' => $employeeName,
+                    'status' => $v['status'],
+                    'comment' => $v['comment_user'] ?? ''
+                ]
+            ];
+        }
+    } catch (Exception $ex) {
+        header('Content-Type: application/json; charset=utf-8');
+        $payload = ['error' => $ex->getMessage(), 'branch' => $branch, 'trace' => $ex->getTraceAsString()];
+        echo json_encode($payload);
+        exit;
+    }
+} catch (Exception $ex) {
+    header('Content-Type: application/json; charset=utf-8');
+    $payload = ['error' => $ex->getMessage(), 'branch' => $branch, 'trace' => $ex->getTraceAsString()];
+    echo json_encode($payload);
+    exit;
+}
+
+$stmt = $pdo->prepare("SELECT * FROM company_holidays WHERE start_date <= ? AND end_date >= ? ORDER BY start_date");
+$stmt->execute([$end, $start]);
+$holidays = $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+foreach ($holidays as $h) {
+    $endInclusive = (new DateTime($h['end_date']))->modify('+1 day')->format('Y-m-d');
+    $events[] = [
+        'id' => 'com_' . $h['id'],
+        'title' => $h['description'] ?: 'Betriebsurlaub',
+        'start' => $h['start_date'],
+        'end' => $endInclusive,
+        'allDay' => true,
+        'color' => '#007bff',
+        'extendedProps' => [
+            'type' => 'company',
+            'description' => $h['description']
+        ]
+    ];
+}
+
+header('Content-Type: application/json; charset=utf-8');
+if ($debugMode) {
+    echo json_encode(['events' => $events, 'meta' => $meta]);
+} else {
+    echo json_encode($events);
+}
+?>
diff --git a/zeiterfassung/company_holidays.php b/zeiterfassung/company_holidays.php
index d0a8b56..230af69 100644
--- a/zeiterfassung/company_holidays.php
+++ b/zeiterfassung/company_holidays.php
@@ -1,90 +1,159 @@
-<?php
-session_start();
-require_once('inc/config.inc.php');
-require_once('inc/functions.inc.php');
-
-$user = check_user();
-if (!is_admin_user()) {
-    die('Zugriff verweigert. Nur Chefs dürfen Betriebsurlaub verwalten.');
-}
-
-// Create table if not exists (optional helper)
-// Administrators can also run the SQL directly in DB. This is just a convenience.
-
-if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['start_date']) && isset($_POST['end_date'])) {
-    $start = $_POST['start_date'];
-    $end = $_POST['end_date'];
-    $desc = trim($_POST['description'] ?? 'Betriebsurlaub');
-
-    $stmt = $pdo->prepare("INSERT INTO company_holidays (start_date, end_date, description, created_by) VALUES (?, ?, ?, ?)");
-    $stmt->execute([$start, $end, $desc, $_SESSION['userid']]);
-
-    header('Location: company_holidays.php');
-    exit();
-}
-
-include 'header.php';
-
-$stmt = $pdo->prepare("SELECT * FROM company_holidays ORDER BY start_date DESC");
-$stmt->execute();
-$holidays = $stmt->fetchAll();
-
-?>
-
-<div class="container">
-    <h2>Betriebsurlaub verwalten</h2>
-
-    <form method="post" class="form-inline mb-3">
-        <div class="form-group mr-2">
-            <label>Von:</label>
-            <input type="date" name="start_date" class="form-control" required>
-        </div>
-        <div class="form-group mr-2">
-            <label>Bis:</label>
-            <input type="date" name="end_date" class="form-control" required>
-        </div>
-        <div class="form-group mr-2">
-            <label>Beschreibung:</label>
-            <input type="text" name="description" class="form-control" placeholder="z. B. Betriebsurlaub Weihnachten">
-        </div>
-        <button class="btn btn-primary">Hinzufügen</button>
-    </form>
-
-    <table class="table table-bordered">
-        <thead>
-            <tr>
-                <th>Von</th>
-                <th>Bis</th>
-                <th>Beschreibung</th>
-                <th>Erstellt von</th>
-                <th>Aktion</th>
-            </tr>
-        </thead>
-        <tbody>
-        <?php foreach ($holidays as $h): ?>
-            <tr>
-                <td><?php echo $h['start_date']; ?></td>
-                <td><?php echo $h['end_date']; ?></td>
-                <td><?php echo htmlspecialchars($h['description']); ?></td>
-                <td><?php
-                    $s = $pdo->prepare("SELECT vorname, nachname FROM users WHERE id = ?");
-                    $s->execute([$h['created_by']]);
-                    $u = $s->fetch();
-                    echo htmlspecialchars($u['vorname'] . ' ' . $u['nachname']);
-                ?></td>
-                <td>
-                    <form method="post" action="deleteCompanyHoliday.php" onsubmit="return confirm('Betriebsurlaub wirklich löschen?');">
-                        <input type="hidden" name="id" value="<?php echo intval($h['id']); ?>">
-                        <button class="btn btn-sm btn-danger">Löschen</button>
-                    </form>
-                </td>
-            </tr>
-        <?php endforeach; ?>
-        </tbody>
-    </table>
-
-</div>
-
-<?php include 'footer.php';
-
-?>
+<?php
+session_start();
+require_once('inc/config.inc.php');
+require_once('inc/functions.inc.php');
+require_once(__DIR__ . '/../inc/company_holiday_sync.inc.php');
+
+$user = check_user();
+if (!is_admin_user()) {
+    die('Zugriff verweigert. Nur Chefs duerfen Betriebsurlaub verwalten.');
+}
+
+$error = '';
+$schemaError = '';
+
+try {
+    vacationSyncEnsureSchema($pdo);
+} catch (Throwable $e) {
+    $schemaError = 'Die Seite konnte das Urlaubsschema nicht automatisch aktualisieren: ' . $e->getMessage();
+}
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['start_date']) && isset($_POST['end_date'])) {
+    $start = trim((string)($_POST['start_date'] ?? ''));
+    $end = trim((string)($_POST['end_date'] ?? ''));
+    $desc = trim((string)($_POST['description'] ?? 'Betriebsurlaub'));
+    $vertretung = trim((string)($_POST['vertretung'] ?? ''));
+    $vertretertelefon = trim((string)($_POST['vertretertelefon'] ?? ''));
+    $vertreteradresse = trim((string)($_POST['vertreteradresse'] ?? ''));
+    $vertreterurl = trim((string)($_POST['vertreterurl'] ?? ''));
+
+    if ($start === '' || $end === '') {
+        $error = 'Bitte Start- und Enddatum angeben.';
+    } elseif ($start > $end) {
+        $error = 'Das Enddatum darf nicht vor dem Startdatum liegen.';
+    } elseif ($vertretung === '' || $vertretertelefon === '' || $vertreteradresse === '' || $vertreterurl === '') {
+        $error = 'Bitte alle Vertreterinformationen vollstaendig ausfuellen.';
+    } elseif ($schemaError !== '') {
+        $error = $schemaError;
+    } else {
+        $stmt = $pdo->prepare("
+            INSERT INTO company_holidays (
+                start_date, end_date, description, vertretung, vertretertelefon, vertreteradresse, vertreterurl, created_by
+            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
+        ");
+        $stmt->execute([
+            $start,
+            $end,
+            $desc,
+            $vertretung,
+            $vertretertelefon,
+            $vertreteradresse,
+            $vertreterurl,
+            $_SESSION['userid']
+        ]);
+        vacationSyncUrlaubFromCompanyHoliday($pdo, (int)$pdo->lastInsertId());
+
+        header('Location: company_holidays.php');
+        exit();
+    }
+}
+
+include 'header.php';
+
+$stmt = $pdo->prepare("SELECT * FROM company_holidays ORDER BY start_date DESC");
+$stmt->execute();
+$holidays = $stmt->fetchAll(PDO::FETCH_ASSOC);
+?>
+
+<div class="container">
+    <h2>Betriebsurlaub verwalten</h2>
+
+    <?php if ($error !== ''): ?>
+    <div class="alert alert-danger"><?php echo htmlspecialchars($error); ?></div>
+    <?php endif; ?>
+    <?php if ($schemaError !== ''): ?>
+    <div class="alert alert-warning"><?php echo htmlspecialchars($schemaError); ?></div>
+    <?php endif; ?>
+
+    <form method="post" class="mb-3">
+        <div class="form-row">
+            <div class="form-group col-md-3">
+                <label>Von:</label>
+                <input type="date" name="start_date" class="form-control" required>
+            </div>
+            <div class="form-group col-md-3">
+                <label>Bis:</label>
+                <input type="date" name="end_date" class="form-control" required>
+            </div>
+            <div class="form-group col-md-6">
+                <label>Beschreibung:</label>
+                <input type="text" name="description" class="form-control" placeholder="z. B. Betriebsurlaub Weihnachten">
+            </div>
+        </div>
+        <div class="form-row">
+            <div class="form-group col-md-6">
+                <label>Vertretung:</label>
+                <input type="text" name="vertretung" class="form-control" required>
+            </div>
+            <div class="form-group col-md-6">
+                <label>Vertretung Telefon:</label>
+                <input type="text" name="vertretertelefon" class="form-control" required>
+            </div>
+        </div>
+        <div class="form-row">
+            <div class="form-group col-md-8">
+                <label>Vertretung Adresse:</label>
+                <input type="text" name="vertreteradresse" class="form-control" required>
+            </div>
+            <div class="form-group col-md-4">
+                <label>Vertretung Webseite:</label>
+                <input type="text" name="vertreterurl" class="form-control" required>
+            </div>
+        </div>
+        <button class="btn btn-primary">Hinzufuegen</button>
+    </form>
+
+    <table class="table table-bordered">
+        <thead>
+            <tr>
+                <th>Von</th>
+                <th>Bis</th>
+                <th>Beschreibung</th>
+                <th>Vertretung</th>
+                <th>Kontakt</th>
+                <th>Erstellt von</th>
+                <th>Aktion</th>
+            </tr>
+        </thead>
+        <tbody>
+        <?php foreach ($holidays as $h): ?>
+            <tr>
+                <td><?php echo htmlspecialchars((string)$h['start_date']); ?></td>
+                <td><?php echo htmlspecialchars((string)$h['end_date']); ?></td>
+                <td><?php echo htmlspecialchars((string)$h['description']); ?></td>
+                <td><?php echo htmlspecialchars((string)$h['vertretung']); ?></td>
+                <td>
+                    <?php echo htmlspecialchars((string)$h['vertretertelefon']); ?><br>
+                    <?php echo htmlspecialchars((string)$h['vertreteradresse']); ?><br>
+                    <?php echo htmlspecialchars((string)$h['vertreterurl']); ?>
+                </td>
+                <td><?php
+                    $s = $pdo->prepare("SELECT vorname, nachname FROM users WHERE id = ?");
+                    $s->execute([$h['created_by']]);
+                    $u = $s->fetch(PDO::FETCH_ASSOC);
+                    echo htmlspecialchars(trim(($u['vorname'] ?? '') . ' ' . ($u['nachname'] ?? '')));
+                ?></td>
+                <td>
+                    <form method="post" action="deleteCompanyHoliday.php" onsubmit="return confirm('Betriebsurlaub wirklich loeschen?');">
+                        <input type="hidden" name="id" value="<?php echo (int)$h['id']; ?>">
+                        <button class="btn btn-sm btn-danger">Loeschen</button>
+                    </form>
+                </td>
+            </tr>
+        <?php endforeach; ?>
+        </tbody>
+    </table>
+
+</div>
+
+<?php include 'footer.php'; ?>
diff --git a/zeiterfassung/deleteCompanyHoliday.php b/zeiterfassung/deleteCompanyHoliday.php
index 879455d..1ba08eb 100644
--- a/zeiterfassung/deleteCompanyHoliday.php
+++ b/zeiterfassung/deleteCompanyHoliday.php
@@ -2,6 +2,7 @@
 session_start();
 require_once('inc/config.inc.php');
 require_once('inc/functions.inc.php');
+require_once(__DIR__ . '/../inc/company_holiday_sync.inc.php');
 
 $user = check_user();
 if (!is_admin_user()) {
@@ -18,9 +19,10 @@ if ($_SERVER['REQUEST_METHOD'] !== 'POST' || !isset($_POST['id'])) {
 
 $id = intval($_POST['id']);
 
+vacationSyncDeleteUrlaubByCompanyHoliday($pdo, $id);
 $stmt = $pdo->prepare("DELETE FROM company_holidays WHERE id = ?");
 $stmt->execute([$id]);
 
 header('Location: company_holidays.php');
 exit;
-?>
\ No newline at end of file
+?>
diff --git a/zeiterfassung/deleteVacation.php b/zeiterfassung/deleteVacation.php
index 451b959..f97aac3 100644
--- a/zeiterfassung/deleteVacation.php
+++ b/zeiterfassung/deleteVacation.php
@@ -1,38 +1,34 @@
-<?php
-session_start();
-require_once('inc/config.inc.php');
-require_once('inc/functions.inc.php');
-
-$user = check_user();
-
-if ($_SERVER['REQUEST_METHOD'] !== 'POST' || !isset($_POST['id'])) {
-    http_response_code(400);
-    die('Bad request');
-}
-
-$id = (int)$_POST['id'];
-$referer = $_POST['referer'] ?? 'urlaubsantrag.php';
-
-// Fetch vacation to verify ownership
-$stmt = $pdo->prepare("SELECT user_id, status FROM vacations WHERE id = ?");
-$stmt->execute([$id]);
-$vac = $stmt->fetch();
-
-if (!$vac) {
-    die('Urlaubseintrag nicht gefunden.');
-}
-
-$isAdmin = is_admin_user();
-
-if (!$isAdmin && $vac['user_id'] != $_SESSION['userid']) {
-    die('Zugriff verweigert.');
-}
-
-// Allow deletion for admins or owner
-$del = $pdo->prepare("DELETE FROM vacations WHERE id = ?");
-$del->execute([$id]);
-
-header('Location: ' . $referer);
-exit();
-
-?>
+<?php
+session_start();
+require_once('inc/config.inc.php');
+require_once('inc/functions.inc.php');
+
+$user = check_user();
+
+if ($_SERVER['REQUEST_METHOD'] !== 'POST' || !isset($_POST['id'])) {
+    http_response_code(400);
+    die('Bad request');
+}
+
+$id = (int)$_POST['id'];
+$referer = $_POST['referer'] ?? 'urlaubsantrag.php';
+
+$stmt = $pdo->prepare("SELECT user_id, status FROM vacations WHERE id = ?");
+$stmt->execute([$id]);
+$vac = $stmt->fetch(PDO::FETCH_ASSOC);
+
+if (!$vac) {
+    die('Urlaubseintrag nicht gefunden.');
+}
+
+$canManageTeamVacations = can_manage_team_vacations();
+if (!$canManageTeamVacations && (int)$vac['user_id'] !== (int)$_SESSION['userid']) {
+    die('Zugriff verweigert.');
+}
+
+$del = $pdo->prepare("DELETE FROM vacations WHERE id = ?");
+$del->execute([$id]);
+
+header('Location: ' . $referer);
+exit();
+?>
diff --git a/zeiterfassung/inc/functions.inc.php b/zeiterfassung/inc/functions.inc.php
index 61c8ecb..fd2b071 100644
--- a/zeiterfassung/inc/functions.inc.php
+++ b/zeiterfassung/inc/functions.inc.php
@@ -145,6 +145,15 @@ function is_admin_user() {
 	$statement->execute(array('id' => $_SESSION['userid']));
 	return ($statement->rowCount() == 1);
 }
+
+/**
+ * Returns true when the user may manage vacations for the team.
+ * In the current Zeiterfassung, team leads are represented by the
+ * existing admin role.
+ */
+function can_manage_team_vacations() {
+	return is_admin_user();
+}
 /**
  * Prüft, ob der Benutzer Bearbeiter ist
  */
@@ -187,4 +196,4 @@ function isValidSequence($sequence) {
 }
 
 
-?>
\ No newline at end of file
+?>
diff --git a/zeiterfassung/urlaubsantrag.php b/zeiterfassung/urlaubsantrag.php
index cde0c5e..d686b54 100644
--- a/zeiterfassung/urlaubsantrag.php
+++ b/zeiterfassung/urlaubsantrag.php
@@ -1,178 +1,241 @@
-<?php
-session_start();
-require_once("inc/config.inc.php");
-require_once("inc/functions.inc.php");
-
-$user = check_user();
-
-if (!isset($_SESSION['userid'])) {
-    die("Kein Benutzer angemeldet.");
-}
-
-$user_id = $_SESSION['userid'];
-$message = "";
-$error = "";
-
-function calculateWorkingDays($start, $end) {
-    $start = new DateTime($start);
-    $end = new DateTime($end);
-    $end->modify('+1 day');
-
-    $interval = new DateInterval('P1D');
-    $period = new DatePeriod($start, $interval, $end);
-
-    $workingDays = 0;
-
-    foreach ($period as $day) {
-        if ($day->format('N') < 6) { // 1 (Mo) - 5 (Fr)
-            $workingDays++;
-        }
-    }
-
-    return $workingDays;
-}
-
-if ($_SERVER["REQUEST_METHOD"] == "POST") {
-
-    $start_date = $_POST['start_date'];
-    $end_date = $_POST['end_date'];
-    $comment = trim($_POST['comment']);
-
-    if (empty($start_date) || empty($end_date)) {
-        $error = "Bitte beide Datumsfelder ausfüllen.";
-    } elseif ($start_date > $end_date) {
-        $error = "Enddatum liegt vor dem Startdatum.";
-    } elseif ($start_date < date("Y-m-d")) {
-        $error = "Urlaub kann nicht in der Vergangenheit beantragt werden.";
-    } else {
-
-        // Überschneidung prüfen
-        $stmt = $pdo->prepare("
-            SELECT COUNT(*) FROM vacations 
-            WHERE user_id = ?
-            AND status != 'abgelehnt'
-            AND (
-                (start_date BETWEEN ? AND ?)
-                OR (end_date BETWEEN ? AND ?)
-                OR (? BETWEEN start_date AND end_date)
-            )
-        ");
-        $stmt->execute([$user_id, $start_date, $end_date, $start_date, $end_date, $start_date]);
-        $exists = $stmt->fetchColumn();
-
-        if ($exists > 0) {
-            $error = "Der Zeitraum überschneidet sich mit einem bestehenden Antrag.";
-        } else {
-
-            $days = calculateWorkingDays($start_date, $end_date);
-
-            $insert = $pdo->prepare("
-                INSERT INTO vacations (user_id, start_date, end_date, days, comment_user)
-                VALUES (?, ?, ?, ?, ?)
-            ");
-
-            $insert->execute([$user_id, $start_date, $end_date, $days, $comment]);
-
-            $message = "Urlaubsantrag erfolgreich eingereicht ($days Werktage).";
-        }
-    }
-}
-?>
-
-<?php include 'header.php'; ?>
-
-<div class="container">
-<div class="row">
-<div class="col-md-8 offset-md-2">
-
-<h2>Urlaubsantrag</h2>
-
-<?php if ($error): ?>
-<div class="alert alert-danger"><?php echo $error; ?></div>
-<?php endif; ?>
-
-<?php if ($message): ?>
-<div class="alert alert-success"><?php echo $message; ?></div>
-<?php endif; ?>
-
-<form method="post">
-
-    <div class="form-group">
-        <label>Von:</label>
-        <input type="date" name="start_date" class="form-control" required>
-    </div>
-
-    <div class="form-group">
-        <label>Bis:</label>
-        <input type="date" name="end_date" class="form-control" required>
-    </div>
-
-    <div class="form-group">
-        <label>Kommentar (optional):</label>
-        <textarea name="comment" class="form-control"></textarea>
-    </div>
-
-    <br>
-
-    <button type="submit" class="btn btn-primary btn-block">
-        Urlaub beantragen
-    </button>
-
-</form>
-
-<hr>
-
-<h4>Meine Anträge</h4>
-
-<?php
-$stmt = $pdo->prepare("
-    SELECT * FROM vacations 
-    WHERE user_id = ?
-    ORDER BY created_at DESC
-");
-$stmt->execute([$user_id]);
-$antraege = $stmt->fetchAll();
-?>
-
-<table class="table table-bordered">
-    <tr>
-        <th>Von</th>
-        <th>Bis</th>
-        <th>Tage</th>
-        <th>Status</th>
-        <th>Aktion</th>
-    </tr>
-
-<?php foreach ($antraege as $a): ?>
-<tr>
-    <td><?php echo $a['start_date']; ?></td>
-    <td><?php echo $a['end_date']; ?></td>
-    <td><?php echo $a['days']; ?></td>
-    <td>
-        <?php
-        if ($a['status'] == 'beantragt') {
-            echo '<span class="badge badge-warning">Beantragt</span>';
-        } elseif ($a['status'] == 'genehmigt') {
-            echo '<span class="badge badge-success">Genehmigt</span>';
-        } else {
-            echo '<span class="badge badge-danger">Abgelehnt</span>';
-        }
-        ?>
-    </td>
-    <td>
-        <form method="post" action="deleteVacation.php" onsubmit="return confirm('Wirklich löschen?');">
-            <input type="hidden" name="id" value="<?php echo $a['id']; ?>">
-            <input type="hidden" name="referer" value="urlaubsantrag.php">
-            <button type="submit" class="btn btn-sm btn-danger">Löschen</button>
-        </form>
-    </td>
-</tr>
-<?php endforeach; ?>
-
-</table>
-
-</div>
-</div>
-</div>
-
-<?php include 'footer.php'; ?>
\ No newline at end of file
+<?php
+session_start();
+require_once("inc/config.inc.php");
+require_once("inc/functions.inc.php");
+
+$user = check_user();
+
+if (!isset($_SESSION['userid'])) {
+    die("Kein Benutzer angemeldet.");
+}
+
+$user_id = (int)$_SESSION['userid'];
+$canManageTeamVacations = can_manage_team_vacations();
+$message = "";
+$error = "";
+$selected_user_id = $user_id;
+
+$selectableUsers = [];
+if ($canManageTeamVacations) {
+    $stmtUsers = $pdo->prepare("
+        SELECT id, vorname, nachname, email
+        FROM users
+        WHERE zeiterfassung = 1
+        ORDER BY nachname, vorname
+    ");
+    $stmtUsers->execute();
+    $selectableUsers = $stmtUsers->fetchAll(PDO::FETCH_ASSOC);
+}
+
+function calculateWorkingDays($start, $end) {
+    $start = new DateTime($start);
+    $end = new DateTime($end);
+    $end->modify('+1 day');
+
+    $interval = new DateInterval('P1D');
+    $period = new DatePeriod($start, $interval, $end);
+
+    $workingDays = 0;
+    foreach ($period as $day) {
+        if ($day->format('N') < 6) {
+            $workingDays++;
+        }
+    }
+
+    return $workingDays;
+}
+
+if ($_SERVER["REQUEST_METHOD"] === "POST") {
+    $start_date = trim((string)($_POST['start_date'] ?? ''));
+    $end_date = trim((string)($_POST['end_date'] ?? ''));
+    $comment = trim((string)($_POST['comment'] ?? ''));
+    $selected_user_id = $canManageTeamVacations ? (int)($_POST['user_id'] ?? $user_id) : $user_id;
+
+    $selectedUser = null;
+    if ($selected_user_id <= 0) {
+        $error = "Bitte einen Mitarbeiter auswaehlen.";
+    } else {
+        $stmtSelectedUser = $pdo->prepare("
+            SELECT id, vorname, nachname
+            FROM users
+            WHERE id = ?
+              AND zeiterfassung = 1
+            LIMIT 1
+        ");
+        $stmtSelectedUser->execute([$selected_user_id]);
+        $selectedUser = $stmtSelectedUser->fetch(PDO::FETCH_ASSOC);
+
+        if (!$selectedUser) {
+            $error = "Der ausgewaehlte Mitarbeiter wurde nicht gefunden.";
+        }
+    }
+
+    if ($error === "" && ($start_date === '' || $end_date === '')) {
+        $error = "Bitte beide Datumsfelder ausfuellen.";
+    } elseif ($error === "" && $start_date > $end_date) {
+        $error = "Enddatum liegt vor dem Startdatum.";
+    } elseif ($error === "" && $start_date < date("Y-m-d")) {
+        $error = "Urlaub kann nicht in der Vergangenheit beantragt werden.";
+    } elseif ($error === "") {
+        $stmt = $pdo->prepare("
+            SELECT COUNT(*)
+            FROM vacations
+            WHERE user_id = ?
+              AND status != 'abgelehnt'
+              AND (
+                  (start_date BETWEEN ? AND ?)
+                  OR (end_date BETWEEN ? AND ?)
+                  OR (? BETWEEN start_date AND end_date)
+              )
+        ");
+        $stmt->execute([$selected_user_id, $start_date, $end_date, $start_date, $end_date, $start_date]);
+        $exists = (int)$stmt->fetchColumn();
+
+        if ($exists > 0) {
+            $error = "Der Zeitraum ueberschneidet sich mit einem bestehenden Antrag.";
+        } else {
+            $days = calculateWorkingDays($start_date, $end_date);
+
+            $insert = $pdo->prepare("
+                INSERT INTO vacations (user_id, start_date, end_date, days, comment_user)
+                VALUES (?, ?, ?, ?, ?)
+            ");
+            $insert->execute([$selected_user_id, $start_date, $end_date, $days, $comment]);
+
+            if ($selected_user_id !== $user_id && $selectedUser) {
+                $message = "Urlaub fuer " . $selectedUser['vorname'] . " " . $selectedUser['nachname'] . " erfolgreich eingereicht ($days Werktage).";
+            } else {
+                $message = "Urlaubsantrag erfolgreich eingereicht ($days Werktage).";
+            }
+        }
+    }
+}
+?>
+
+<?php include 'header.php'; ?>
+
+<div class="container">
+<div class="row">
+<div class="col-md-8 offset-md-2">
+
+<h2>Urlaubsantrag</h2>
+
+<?php if ($error): ?>
+<div class="alert alert-danger"><?php echo htmlspecialchars($error); ?></div>
+<?php endif; ?>
+
+<?php if ($message): ?>
+<div class="alert alert-success"><?php echo htmlspecialchars($message); ?></div>
+<?php endif; ?>
+
+<form method="post">
+
+    <?php if ($canManageTeamVacations): ?>
+    <div class="form-group">
+        <label>Mitarbeiter:</label>
+        <select name="user_id" class="form-control" required>
+            <?php foreach ($selectableUsers as $employee): ?>
+                <?php $employeeId = (int)$employee['id']; ?>
+                <option value="<?php echo $employeeId; ?>" <?php echo ($selected_user_id === $employeeId) ? 'selected' : ''; ?>>
+                    <?php echo htmlspecialchars(trim($employee['nachname'] . ', ' . $employee['vorname'] . ' | ' . $employee['email'])); ?>
+                </option>
+            <?php endforeach; ?>
+        </select>
+    </div>
+    <?php endif; ?>
+
+    <div class="form-group">
+        <label>Von:</label>
+        <input type="date" name="start_date" class="form-control" required>
+    </div>
+
+    <div class="form-group">
+        <label>Bis:</label>
+        <input type="date" name="end_date" class="form-control" required>
+    </div>
+
+    <div class="form-group">
+        <label>Kommentar (optional):</label>
+        <textarea name="comment" class="form-control"></textarea>
+    </div>
+
+    <br>
+
+    <button type="submit" class="btn btn-primary btn-block">
+        <?php echo $canManageTeamVacations ? 'Urlaub eintragen' : 'Urlaub beantragen'; ?>
+    </button>
+
+</form>
+
+<hr>
+
+<h4><?php echo $canManageTeamVacations ? 'Urlaubseintraege' : 'Meine Antraege'; ?></h4>
+
+<?php
+$listSql = "
+    SELECT v.*, u.vorname, u.nachname
+    FROM vacations v
+    JOIN users u ON u.id = v.user_id
+";
+
+if ($canManageTeamVacations) {
+    $listSql .= " ORDER BY v.created_at DESC";
+    $stmt = $pdo->prepare($listSql);
+    $stmt->execute();
+} else {
+    $listSql .= " WHERE v.user_id = ? ORDER BY v.created_at DESC";
+    $stmt = $pdo->prepare($listSql);
+    $stmt->execute([$user_id]);
+}
+
+$antraege = $stmt->fetchAll(PDO::FETCH_ASSOC);
+?>
+
+<table class="table table-bordered">
+    <tr>
+        <?php if ($canManageTeamVacations): ?>
+        <th>Mitarbeiter</th>
+        <?php endif; ?>
+        <th>Von</th>
+        <th>Bis</th>
+        <th>Tage</th>
+        <th>Status</th>
+        <th>Aktion</th>
+    </tr>
+
+<?php foreach ($antraege as $a): ?>
+<tr>
+    <?php if ($canManageTeamVacations): ?>
+    <td><?php echo htmlspecialchars(trim($a['vorname'] . ' ' . $a['nachname'])); ?></td>
+    <?php endif; ?>
+    <td><?php echo htmlspecialchars((string)$a['start_date']); ?></td>
+    <td><?php echo htmlspecialchars((string)$a['end_date']); ?></td>
+    <td><?php echo (int)$a['days']; ?></td>
+    <td>
+        <?php
+        if ($a['status'] === 'beantragt' || $a['status'] === null || $a['status'] === '') {
+            echo '<span class="badge badge-warning">Beantragt</span>';
+        } elseif ($a['status'] === 'genehmigt') {
+            echo '<span class="badge badge-success">Genehmigt</span>';
+        } else {
+            echo '<span class="badge badge-danger">Abgelehnt</span>';
+        }
+        ?>
+    </td>
+    <td>
+        <form method="post" action="deleteVacation.php" onsubmit="return confirm('Wirklich loeschen?');">
+            <input type="hidden" name="id" value="<?php echo (int)$a['id']; ?>">
+            <input type="hidden" name="referer" value="urlaubsantrag.php">
+            <button type="submit" class="btn btn-sm btn-danger">Loeschen</button>
+        </form>
+    </td>
+</tr>
+<?php endforeach; ?>
+
+</table>
+
+</div>
+</div>
+</div>
+
+<?php include 'footer.php'; ?>
diff --git a/zeiterfassung/vacations_calendar.php b/zeiterfassung/vacations_calendar.php
index 7e60406..01e5f73 100644
--- a/zeiterfassung/vacations_calendar.php
+++ b/zeiterfassung/vacations_calendar.php
@@ -41,16 +41,17 @@ document.addEventListener('DOMContentLoaded', function() {
             var url = 'api/vacations.php?start=' + info.startStr + '&end=' + info.endStr;
             fetch(url).then(function(res){ return res.json(); }).then(function(data){ successCallback(data); }).catch(function(err){ failureCallback(err); });
         },
-        eventClick: function(info) {
-            var ev = info.event;
-            var props = ev.extendedProps;
-            var html = '<strong>' + ev.title + '</strong><br>' + ev.start.toLocaleDateString() + ' - ' + (new Date(ev.end).toLocaleDateString()) + '<br>';
-            if (props.type === 'user') {
-                html += 'Status: ' + (props.status || '') + '<br>';
-                html += 'Kommentar: ' + (props.comment || '') + '<br>';
-            } else if (props.type === 'company') {
-                html += 'Beschreibung: ' + (props.description || '') + '<br>';
-            }
+        eventClick: function(info) {
+            var ev = info.event;
+            var props = ev.extendedProps;
+            var html = '<strong>' + ev.title + '</strong><br>' + ev.start.toLocaleDateString() + ' - ' + (new Date(ev.end).toLocaleDateString()) + '<br>';
+            if (props.type === 'user') {
+                html += 'Mitarbeiter: ' + (props.employee_name || '') + '<br>';
+                html += 'Status: ' + (props.status || '') + '<br>';
+                html += 'Kommentar: ' + (props.comment || '') + '<br>';
+            } else if (props.type === 'company') {
+                html += 'Beschreibung: ' + (props.description || '') + '<br>';
+            }
             document.getElementById('detailsContent').innerHTML = html;
             document.getElementById('eventDetails').style.display = 'block';
         }
diff --git a/zeiterfassung/vacations_calendar_all.php b/zeiterfassung/vacations_calendar_all.php
index fbc670b..eb23a14 100644
--- a/zeiterfassung/vacations_calendar_all.php
+++ b/zeiterfassung/vacations_calendar_all.php
@@ -1,59 +1,63 @@
-<?php
-session_start();
-require_once('inc/config.inc.php');
-require_once('inc/functions.inc.php');
-
-// allow any logged-in user to view the team calendar (read-only)
-$user = check_user();
-
-include 'header.php';
-?>
-
-<div class="container">
-    <h2>Team Urlaubskalender</h2>
-    <div id="calendar"></div>
-    <br>
-    <div>
-        <span class="badge badge-success">genehmigt</span>
-        <span class="badge badge-primary">Betriebsurlaub</span>
-    </div>
-    <br>
-    <div id="eventDetails" style="display:none;">
-        <h4>Details</h4>
-        <div id="detailsContent"></div>
-    </div>
-</div>
-
-<link href='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.css' rel='stylesheet' />
-<script src='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.js'></script>
-<script>
-document.addEventListener('DOMContentLoaded', function() {
-    var calendarEl = document.getElementById('calendar');
-
-    var calendar = new FullCalendar.Calendar(calendarEl, {
-        initialView: 'dayGridMonth',
-        firstDay: 1,
-        height: 650,
-        events: function(info, successCallback, failureCallback) {
-            var url = 'api/vacations.php?start=' + info.startStr + '&end=' + info.endStr + '&public=1&public_all=1';
-            fetch(url).then(function(res){ return res.json(); }).then(function(data){ successCallback(data); }).catch(function(err){ failureCallback(err); });
-        },
-        eventClick: function(info) {
-            var ev = info.event;
-            var props = ev.extendedProps;
-            var html = '<strong>' + ev.title + '</strong><br>' + ev.start.toLocaleDateString() + ' - ' + (new Date(ev.end).toLocaleDateString()) + '<br>';
-            if (props.type === 'user') {
-                html += 'Mitarbeiter-ID: ' + (props.user_id || '') + '<br>';
-            } else if (props.type === 'company') {
-                html += 'Beschreibung: ' + (props.description || '') + '<br>';
-            }
-            document.getElementById('detailsContent').innerHTML = html;
-            document.getElementById('eventDetails').style.display = 'block';
-        }
-    });
-
-    calendar.render();
-});
-</script>
-
-<?php include 'footer.php'; ?>
+<?php
+session_start();
+require_once('inc/config.inc.php');
+require_once('inc/functions.inc.php');
+
+$user = check_user();
+
+include 'header.php';
+?>
+
+<div class="container">
+    <h2>Team Urlaubskalender</h2>
+    <div id="calendar"></div>
+    <br>
+    <div>
+        <span class="badge badge-success">genehmigt</span>
+        <span class="badge badge-warning">beantragt</span>
+        <span class="badge badge-primary">Betriebsurlaub</span>
+    </div>
+    <br>
+    <div id="eventDetails" style="display:none;">
+        <h4>Details</h4>
+        <div id="detailsContent"></div>
+    </div>
+</div>
+
+<link href='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.css' rel='stylesheet' />
+<script src='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.js'></script>
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+    var calendarEl = document.getElementById('calendar');
+
+    var calendar = new FullCalendar.Calendar(calendarEl, {
+        initialView: 'dayGridMonth',
+        firstDay: 1,
+        height: 650,
+        events: function(info, successCallback, failureCallback) {
+            var url = 'api/vacations.php?start=' + info.startStr + '&end=' + info.endStr + '&public=1&public_all=1';
+            fetch(url).then(function(res){ return res.json(); }).then(function(data){ successCallback(data); }).catch(function(err){ failureCallback(err); });
+        },
+        eventClick: function(info) {
+            var ev = info.event;
+            var props = ev.extendedProps;
+            var html = '<strong>' + ev.title + '</strong><br>' + ev.start.toLocaleDateString() + ' - ' + (new Date(ev.end).toLocaleDateString()) + '<br>';
+            if (props.type === 'user') {
+                html += 'Mitarbeiter: ' + (props.employee_name || ev.title || '') + '<br>';
+                html += 'Status: ' + (props.status || '') + '<br>';
+                if (props.comment) {
+                    html += 'Kommentar: ' + props.comment + '<br>';
+                }
+            } else if (props.type === 'company') {
+                html += 'Beschreibung: ' + (props.description || '') + '<br>';
+            }
+            document.getElementById('detailsContent').innerHTML = html;
+            document.getElementById('eventDetails').style.display = 'block';
+        }
+    });
+
+    calendar.render();
+});
+</script>
+
+<?php include 'footer.php'; ?>