diff --git a/application/controllers/system/MigrateKalender.php b/application/controllers/system/MigrateKalender.php
index 67de262dd..71a7d189f 100644
--- a/application/controllers/system/MigrateKalender.php
+++ b/application/controllers/system/MigrateKalender.php
@@ -32,6 +32,42 @@ class MigrateKalender extends CLI_Controller
 	/**
 	 * Everything has a beginning
 	 */
+	public function refreshTablesAndFullMigrateOfStundenplanReservierung($von, $bis = null, $studiengang_kz = null, $ort_kurzbz = null)
+	{
+		if (defined('CI_ENVIRONMENT') && CI_ENVIRONMENT === 'production')
+		{
+			echo "This script is not allowed to run in production environment.\n";
+			return;
+		}
+
+		echo "Refreshing calendar related tables...\n";
+		$this->resetBeforeNewStundenplanReservierungImport();
+		echo "Calendar related tables refreshed successfully.\n\n";
+
+		echo "Starting full migration of Stundenplan and Reservierung from $von to " . ($bis ?? '2100-12-31') . "...\n";
+		$this->fullMigrateOfStundenplanReservierung($von, $bis, $studiengang_kz, $ort_kurzbz);
+		echo "Full migration of Stundenplan and Reservierung completed successfully.\n";
+	}
+
+	public function fullMigrateOfStundenplanReservierung($von, $bis = null, $studiengang_kz = null, $ort_kurzbz = null)
+	{
+		echo "Starting migration of Stundenplan from $von to " . ($bis ?? '2100-12-31') . "...\n";
+		$this->migrateStundenplan($von, $bis, $studiengang_kz);
+		echo "Stundenplan migration completed successfully.\n\n";
+
+		echo "Starting migration of Reservierung from $von to " . ($bis ?? '2100-12-31') . "...\n";
+		$this->migrateReservierung($von, $bis, $ort_kurzbz);
+		echo "Reservierung migration completed successfully.\n\n";
+
+		echo "Starting migration of Stundenplan Betriebsmittel entries...\n";
+		$this->migrateStundenplanBetriebsmittelEntries();
+		echo "Stundenplan Betriebsmittel entries migration completed successfully.\n\n";
+
+		echo "Starting to add title values as tags to calendar entries...\n";
+		$this->addTitleValuesAsTagsToKalenderEntries();
+		echo "Adding title values as tags to calendar entries completed successfully.\n\n";
+	}
+
 	public function migrateStundenplan($von, $bis = null, $studiengang_kz = null)
 	{
 		if (is_null($von))
@@ -333,6 +369,121 @@ class MigrateKalender extends CLI_Controller
 		$dbModel->db->query($query);
 	}
 
+	public function addTitleValuesAsTagsToKalenderEntries() {
+		$dbModel = new DB_Model();
+
+		
+		$query = "SELECT 
+				k.eindeutige_kalender_gruppen_id,
+				ARRAY_AGG(DISTINCT(spd.titel) ORDER BY spd.titel) AS titel,
+				MAX(spd.updateamum) AS updateamum
+			FROM lehre.tbl_stundenplandev spd
+			JOIN sync.tbl_stundenplandev_kalender spdk ON spd.stundenplandev_id = spdk.stundenplandev_id
+			JOIN lehre.tbl_kalender k ON k.kalender_id = spdk.kalender_id
+			WHERE k.typ = 'lehreinheit' AND k.eindeutige_kalender_gruppen_id IS NOT NULL AND spd.titel IS NOT NULL
+			GROUP BY k.eindeutige_kalender_gruppen_id";
+
+		$result = $dbModel->execReadOnlyQuery($query);
+
+		if (isError($result)) {
+			error("Error while fetching title values for adding as tags: " . getError($result));
+			return;
+		}
+		if (!hasData($result)) {
+			error("No title values found for adding as tags.");
+			return;
+		}
+
+		$data = getData($result);
+
+		foreach($data as $block) {
+			$eindeutige_kalender_gruppen_id = $block->eindeutige_kalender_gruppen_id;
+			$notizText = implode(' - ', array_filter($block->titel, function($titel) {
+				return !empty(trim($titel));
+			}));
+
+			if (!empty($notizText)) {
+				$this->addTag($eindeutige_kalender_gruppen_id, $notizText, $block->updateamum);
+			}
+		}
+	}
+
+	private function resetBeforeNewStundenplanReservierungImport()
+	{
+		if (defined('CI_ENVIRONMENT') && CI_ENVIRONMENT === 'production')
+		{
+			echo "This script is not allowed to run in production environment.\n";
+			return;
+		}
+
+		$db = new DB_Model();
+
+		$db->db->trans_start();
+
+		$db->db->query('DELETE FROM sync.tbl_stundenplandev_kalender');
+		$db->db->query('DELETE FROM sync.tbl_reservierung_kalender');
+
+		$db->db->query("DELETE FROM lehre.tbl_kalender_event_teilnehmer
+			WHERE kalender_id IN (
+				SELECT kalender_id
+				FROM lehre.tbl_kalender
+				WHERE typ = 'reservierung'
+			)");
+
+		$db->db->query("DELETE FROM lehre.tbl_kalender_event
+			WHERE kalender_id IN (
+				SELECT kalender_id
+				FROM lehre.tbl_kalender
+				WHERE typ = 'reservierung'
+			)");
+
+		$db->db->query("DELETE FROM lehre.tbl_kalender_lehreinheit
+			WHERE kalender_id IN (
+				SELECT kalender_id
+				FROM lehre.tbl_kalender
+				WHERE typ = 'lehreinheit' OR typ = 'reservierung'
+			)");
+
+		$db->db->query("DELETE FROM lehre.tbl_kalender_ort
+			WHERE kalender_id IN (
+				SELECT kalender_id
+				FROM lehre.tbl_kalender
+				WHERE typ IN ('lehreinheit', 'reservierung')
+			)");
+
+		$db->db->query("DELETE FROM public.tbl_notiz
+			WHERE notiz_id IN (
+				SELECT notiz_id
+				FROM public.tbl_notizzuordnung
+				WHERE eindeutige_kalender_gruppen_id IN (
+					SELECT eindeutige_kalender_gruppen_id
+					FROM lehre.tbl_kalender
+				)
+			)");
+
+		$db->db->query("DELETE FROM public.tbl_notizzuordnung
+			WHERE eindeutige_kalender_gruppen_id IN (
+				SELECT eindeutige_kalender_gruppen_id
+				FROM lehre.tbl_kalender
+			)");
+		
+		$db->db->query("DELETE FROM lehre.tbl_betriebsmittel_kalender
+			WHERE eindeutige_kalender_gruppen_id IN (
+				SELECT eindeutige_kalender_gruppen_id
+				FROM lehre.tbl_kalender
+			)");
+
+		$db->db->query("DELETE FROM lehre.tbl_kalender
+			WHERE typ IN ('lehreinheit', 'reservierung')");
+
+		$db->db->trans_complete();
+
+		if ($db->db->trans_status() === false)
+			return error('Reset before new import failed');
+
+		return success('Migration data reset successfully');
+	}
+
 	private function setKalendarEntriesGroupIDs() {
 		$dbModel = new DB_Model();
 
@@ -607,4 +758,129 @@ class MigrateKalender extends CLI_Controller
 			);
 		}
 	}
+
+	private function addTag($eindeutige_kalender_gruppen_id, $notizText, $lastUpdatedInOldSystem): bool
+	{
+		$notizType = 'hinweis';
+		$insertvonMockUser = 'oldToNewTempusMigration';
+		
+		if (is_null($eindeutige_kalender_gruppen_id) || empty($eindeutige_kalender_gruppen_id)) {
+			var_dump("Error: eindeutige_kalender_gruppen_id is null or empty.");
+			return false;
+		}
+
+		$this->load->model('person/Notiz_model', 'NotizModel');
+		$this->load->model('system/Notiztyp_model', 'NotiztypModel');
+		$this->load->model('person/Notizzuordnung_model', 'NotizzuordnungModel');
+
+		$checkTyp = $this->NotiztypModel->loadWhere(array('typ_kurzbz' => $notizType));
+
+		if (isError($checkTyp))
+		{
+			error("Error occurred while checking Notiztyp: " . $checkTyp->message);
+			return false;
+		}
+
+		if (!hasData($checkTyp))
+		{
+			error("Notiztyp 'hinweis' does not exist. Please create it before adding tags.");
+			return false;
+		}
+		 
+
+		$this->NotizzuordnungModel->addJoin('tbl_notiz', 'tbl_notiz.notiz_id = tbl_notizzuordnung.notiz_id', 'LEFT');
+		$this->NotizzuordnungModel->db->where('tbl_notiz.typ', $notizType);
+		$this->NotizzuordnungModel->db->where('tbl_notiz.insertvon', $insertvonMockUser);
+		$oldNotizZuordnung = $this->NotizzuordnungModel->loadWhere(array('eindeutige_kalender_gruppen_id' => $eindeutige_kalender_gruppen_id));
+		if (isError($oldNotizZuordnung))
+		{
+			error("Error occurred while checking Notizzuordnung: " . $oldNotizZuordnung->message);
+			return false;
+		}
+		if (hasData($oldNotizZuordnung))
+		{
+			return $this->updateTag($eindeutige_kalender_gruppen_id, $notizText, $lastUpdatedInOldSystem);
+		}
+
+		
+		$insertResult = $this->NotizModel->insert(array(
+			'titel' => 'TAG',
+			'text' => $notizText,
+			'verfasser_uid' => null,
+			'erledigt' => false,
+			'insertamum' => date('Y-m-d H:i:s'),
+			'insertvon' => $insertvonMockUser,
+			'typ' => $notizType
+		));
+
+		if (isError($insertResult))
+		{
+			error("Error occurred while inserting Notiz: " . $insertResult->message);
+			return false;
+		}
+
+		$insertZuordnung = $this->NotizzuordnungModel->insert(array(
+			'notiz_id' => $insertResult->retval,
+			'eindeutige_kalender_gruppen_id' => $eindeutige_kalender_gruppen_id
+		));
+
+		if (isError($insertZuordnung)) 
+		{
+			error("Error occurred while inserting Notizzuordnung: " . $insertZuordnung->message);
+			return false;
+		}
+
+		return true;
+	}
+
+	private function updateTag($eindeutige_kalender_gruppen_id, $notizText, $lastUpdatedInOldSystem)
+	{
+		$notizType = 'hinweis';
+		$insertvonMockUser = 'oldToNewTempusMigration';
+		
+		$this->NotizzuordnungModel->addJoin('tbl_notiz', 'tbl_notiz.notiz_id = tbl_notizzuordnung.notiz_id', 'LEFT');
+		$this->NotizzuordnungModel->db->where('tbl_notiz.typ', $notizType);
+		$this->NotizzuordnungModel->db->where('tbl_notiz.insertvon', $insertvonMockUser);
+		$notizZuordnungRes = $this->NotizzuordnungModel->loadWhere(array('eindeutige_kalender_gruppen_id' => $eindeutige_kalender_gruppen_id));
+		if (isError($notizZuordnungRes))
+		{
+			error("Error occurred while loading Notizzuordnung: " . $notizZuordnungRes->message);
+			return false;
+		}
+
+
+		$tag = $this->NotizModel->loadWhere(array('notiz_id' => $notizZuordnungRes->retval[0]->notiz_id));
+		if (isError($tag))
+		{
+			error("Error occurred while loading Notiz: " . $tag->message);
+			return false;
+		}
+
+		if (!hasData($tag))
+		{
+			error("Error occurred while loading Notiz: " . $tag->message);
+			return false;
+		}
+
+		$adjustedLastUpdatedInOldSystem = date('Y-m-d H:i:s', strtotime($lastUpdatedInOldSystem) + 5);
+		if ($tag->retval[0]->updateamum >= $adjustedLastUpdatedInOldSystem)
+		{
+			return true;
+		}
+
+		$updateData = $this->NotizModel->update(array('notiz_id' => $tag->retval[0]->notiz_id),
+			array('text' => $notizText,
+				'updateamum' => date('Y-m-d H:i:s'),
+				'updatevon' => $insertvonMockUser,
+				'bearbeiter_uid' => null,
+			)
+		);
+		if (isError($updateData))
+		{
+			error("Error occurred while updating Notiz: " . $updateData->message);
+			return false;
+		}
+
+		return true;
+	}
 }
diff --git a/application/libraries/KalenderLib.php b/application/libraries/KalenderLib.php
index 623784c9d..935dfebb6 100644
--- a/application/libraries/KalenderLib.php
+++ b/application/libraries/KalenderLib.php
@@ -34,13 +34,27 @@ class KalenderLib
 
 	}
 
-	private function _getBasePlan($start_date, $end_date)
+	private function _buildFilteredKalenderCte($start_date, $end_date)
+	{
+		$end_date = date('Y-m-d', strtotime($end_date . ' +1 day'));
+
+		return sprintf(
+			'WITH filtered_kalender AS MATERIALIZED (
+				SELECT *
+				FROM lehre.tbl_kalender
+				WHERE von >= timestamp %s
+					AND bis < timestamp %s
+			)',
+			$this->_ci->KalenderModel->db->escape(date('Y-m-d H:i:s', strtotime($start_date))),
+			$this->_ci->KalenderModel->db->escape(date('Y-m-d H:i:s', strtotime($end_date)))
+		);
+	}
+
+	private function _buildBasePlanQuery()
 	{
 		$language = $this->getLanguageIndex();
 		$index_bezeichnung_mehrsprachig = $language - 1;
 
-		$end_date = date('Y-m-d', strtotime($end_date . ' +1 day'));
-
 		$this->_ci->KalenderModel->addSelect('tbl_kalender.kalender_id,
 			tbl_kalender.eindeutige_kalender_gruppen_id,
 			tbl_kalender.status_kurzbz,
@@ -139,6 +153,7 @@ class KalenderLib
 		$this->_ci->KalenderModel->addJoin('public.tbl_benutzer resevierung_benutzer', 'reservierung_ma.mitarbeiter_uid = resevierung_benutzer.uid', 'LEFT');
 		$this->_ci->KalenderModel->addJoin('public.tbl_person reservierung_person', 'reservierung_person.person_id = resevierung_benutzer.person_id', 'LEFT');
 
+
 		$this->_ci->KalenderModel->addJoin('lehre.tbl_lehreinheitgruppe', 'tbl_lehreinheit.lehreinheit_id = tbl_lehreinheitgruppe.lehreinheit_id', 'LEFT');
 		$this->_ci->KalenderModel->addJoin('public.tbl_gruppe le_gruppe', 'tbl_lehreinheitgruppe.gruppe_kurzbz = le_gruppe.gruppe_kurzbz', 'LEFT');
 		$this->_ci->KalenderModel->addJoin('public.tbl_lehrverband le_lehrverband',
@@ -216,12 +231,17 @@ class KalenderLib
 		$this->_ci->KalenderModel->db->join('lehre.tbl_stunde vonstunde', 'tbl_kalender.von::time = vonstunde.beginn', 'LEFT', FALSE);
 		$this->_ci->KalenderModel->db->join('lehre.tbl_stunde bisstunde', 'tbl_kalender.bis::time = bisstunde.ende', 'LEFT', FALSE);
 
-		$this->_ci->KalenderModel->db->where('tbl_kalender.von >=', $start_date);
-		$this->_ci->KalenderModel->db->where('tbl_kalender.bis <', $end_date);
-
 		$this->_ci->KalenderModel->addOrder('tbl_kalender.eindeutige_kalender_gruppen_id', 'DESC');
 	}
 
+	private function _loadFilteredBasePlan($start_date, $end_date)
+	{
+		$query = $this->_buildFilteredKalenderCte($start_date, $end_date) . "\n" .
+			$this->_ci->KalenderModel->db->get_compiled_select('filtered_kalender AS tbl_kalender');
+
+		return $this->_ci->KalenderModel->execReadOnlyQuery($query);
+	}
+
 	private function _mapEvents($data, $collisionCheck = true)
 	{
 		$stundenplan_data = [];
@@ -369,10 +389,10 @@ class KalenderLib
 	}
 	public function getPlanByOrt($start_date, $end_date, $ort)
 	{
-		$this->_getBasePlan($start_date, $end_date);
+		$this->_buildBasePlanQuery();
 
 		$this->_ci->KalenderModel->db->where('tbl_kalender_ort.ort_kurzbz', $ort);
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($start_date, $end_date);
 
 		return $this->_mapEvents($data);
 	}
@@ -382,7 +402,7 @@ class KalenderLib
 		$start_date = date('Y-m-d', strtotime($start_date));
 		$end_date = date('Y-m-d', strtotime($end_date . ' +1 day'));
 
-		$this->_getBasePlan($start_date, $end_date);
+		$this->_buildBasePlanQuery();
 
 		$this->_ci->KalenderModel->db->where('NOT EXISTS (
 											SELECT 1 FROM lehre.tbl_kalender nachfolger
@@ -414,7 +434,7 @@ class KalenderLib
 			$this->_ci->KalenderModel->db->group_end();
 		}
 
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($start_date, $end_date);
 		return $this->_mapEvents($data, false);
 	}
 
@@ -430,14 +450,14 @@ class KalenderLib
 
 		$kalender_entry = getData($kalender_entry)[0];
 
-		$this->_getBasePlan($kalender_entry->von, $kalender_entry->bis);
+		$this->_buildBasePlanQuery();
 		$this->_ci->KalenderModel->db->where('tbl_kalender.kalender_id', $kalender_entry->kalender_id);
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($kalender_entry->von, $kalender_entry->bis);
 		return $this->_mapEvents($data);
 	}
 	public function getPlanForPlanner($start_date, $end_date, $ort = null, $uids = null, $studiengaenge = null)
 	{
-		$this->_getBasePlan($start_date, $end_date);
+		$this->_buildBasePlanQuery();
 
 		if (!is_null($ort))
 		{
@@ -540,18 +560,18 @@ class KalenderLib
 			) AS has_assigned_resources"
 		]);
 		
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($start_date, $end_date);
 
 		return $this->_mapEvents($data);
 	}
 
 	public function getPlanForStudent($start_date, $end_date)
 	{
-		$this->_getBasePlan($start_date, $end_date);
+		$this->_buildBasePlanQuery();
 
 		$this->_ci->KalenderModel->db->where_in('status_kurzbz', array('live', 'to_delete_live'));
 
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($start_date, $end_date);
 
 		return $this->_mapEvents($data);
 	}
@@ -559,7 +579,7 @@ class KalenderLib
 
 	public function getPlanForLecturer($start_date, $end_date)
 	{
-		$this->_getBasePlan($start_date, $end_date);
+		$this->_buildBasePlanQuery();
 
 		$this->_ci->KalenderModel->addJoin(
 			'lehre.tbl_kalender neuerer',
@@ -571,7 +591,7 @@ class KalenderLib
 			OR (tbl_kalender.status_kurzbz = 'preview' AND neuerer.kalender_id IS NULL)
 			OR (tbl_kalender.status_kurzbz = 'live' AND neuerer.kalender_id IS NULL)
 		)", NULL, FALSE);
-		$data = $this->_ci->KalenderModel->load();
+		$data = $this->_loadFilteredBasePlan($start_date, $end_date);
 
 		return $this->_mapEvents($data);
 	}
@@ -1840,7 +1860,7 @@ class KalenderLib
 			else
 			{
 
-				if (!isEmptyArray($kalender_entry->ort_kurzbz))
+				if (!isEmptyArray($kalender_entry->ort_kurzbz) || !isEmptyString($kalender_entry->location))
 				{
 					$result = $this->_deleteOrtEntry($kalender_entry);
 					if (isError($result))
diff --git a/system/dbupdate_3.4.php b/system/dbupdate_3.4.php
index 4b1468906..5e947ff25 100644
--- a/system/dbupdate_3.4.php
+++ b/system/dbupdate_3.4.php
@@ -101,7 +101,6 @@ require_once('dbupdate_3.4/68530_Dashboard_Cleanup.php');
 require_once('dbupdate_3.4/77375_ressourcen.php');
 require_once('dbupdate_3.4/78052_tempus_tag_events.php');
 require_once('dbupdate_3.4/78318_rename_column_of_eindeutige_gruppen_id_to_eindeutige_kalender_gruppen_id_in_tbl_kalender.php');
-require_once('dbupdate_3.4/78318_rename_column_of_eindeutige_gruppen_id_to_eindeutige_kalender_gruppen_id_in_tbl_kalender.php');
 require_once('dbupdate_3.4/75959_StudVw_Automatische_Tags.php');
 require_once('dbupdate_3.4/76160_lvv_favorites.php');
 require_once('dbupdate_3.4/77080_tabulator_presets_table.php');