diff --git a/classes/helper.php b/classes/helper.php
index 43e74f5b..aba6f506 100644
--- a/classes/helper.php
+++ b/classes/helper.php
@@ -850,6 +850,7 @@ public function set_tool_config(object|int $pageorid, string $name, string $valu
 
         // Lastupdated timestamp hast to be reset in cache.
         $this->clear_caches($page->id);
+        $this->notify_data_changed($page, 'settings');
     }
 
     /**
@@ -1135,8 +1136,8 @@ public function store_answer(
         $this->clear_caches($pageid);
         $this->get_answers($table, $pageid, $answercolumn);
         $this->get_answers_grouped($table, ['pageid' => $pageid], $answercolumn);
-        $this->get_page_last_update_time($pageid, true);
-        $this->get_page_last_update_time($pageid, false);
+        $this->notify_data_changed($this->get_page($pageid), 'answers', true);
+        $this->notify_data_changed($this->get_page($pageid), 'answers', false);
         return $answerids;
     }
 
@@ -1161,6 +1162,7 @@ public function delete_all_answers(string $table, int $pageid): bool {
         $params = ['pageid' => $pageid];
         $return = $DB->delete_records($table, $params);
         $this->clear_caches($pageid);
+        $this->notify_data_changed($this->get_page($pageid), 'answers');
         return $return;
     }
 
@@ -1197,6 +1199,7 @@ public function delete_single_answer(string $table, int $pageid, int $answerid):
         $params = ['pageid' => $pageid, 'id' => $answerid];
         $return = $DB->delete_records($table, $params);
         $this->clear_caches($pageid);
+        $this->notify_data_changed($this->get_page($pageid), 'answers');
         return $return;
     }
 
@@ -1235,6 +1238,7 @@ public function delete_answers_of_user(string $table, int $pageid, int $userid):
         $params = ['pageid' => $pageid, $toolhelper->get_answer_userid_column() => $userid];
         $return = $DB->delete_records($table, $params);
         $this->clear_caches($pageid);
+        $this->notify_data_changed($page, 'answers');
         return $return;
     }
 
@@ -1324,112 +1328,101 @@ public function get_answers_grouped(string $table, array $params, string $answer
     }
 
     /**
-     * Get the lastupdated timestamp.
+     * Notify, that data changed. This sets a new timestamp to the cache.
+     * Clients then knew, there is someting new, and they have to update this.
      *
-     * @param int|object $pageorid
+     * @param object $page
+     * @param string $identifier
      * @param bool $ignoreanswers
-     * @return mixed
+     * @return void
      */
-    public function get_page_last_update_time(int|object $pageorid, bool $ignoreanswers = false): string|int {
-        global $USER;
-
-        $page = $pageorid;
-        if (!is_object($page)) {
-            $page = $this->get_page($page);
-        }
-
-        if (empty($page)) {
-            return 0;
-        }
-
-        // We only want to deliver results if the teacher allowed to view it.
-        $instance = self::get_instance_by_pageid($page->id);
-        $cm = self::get_cm_by_instance($instance);
-        if (
-            empty($this->get_tool_config($page->id, 'showonteacherpermission'))
-            && !has_capability('mod/mootimeter:moderator', \context_module::instance($cm->id))
-        ) {
-            return 0;
-        }
+    public function notify_data_changed(object $page, string $identifier  = '', bool $ignoreanswers = false): void {
 
-        $settingslastupdated = $this->get_lastupdate_tool_settings($page);
-        $answerslastupdated = $this->get_lastupdate_answers($page, $ignoreanswers);
-
-        return $settingslastupdated + $answerslastupdated;
+        $cache = \cache::make('mod_mootimeter', 'lastupdated');
+        $cachekey = 'lastupdate_' . $identifier . '_' . (int) $ignoreanswers . '_' . $page->id;
+        \local_debugger\performance\debugger::print_debug_backtrace('test', 'data changed_' . $identifier, time());
+        $cache->set($cachekey, time());
     }
 
     /**
-     * Get the last updated timestamp of the answers.
+     * Get the recent data changed timestamp
      *
      * @param object $page
+     * @param string $identifier
      * @param bool $ignoreanswers
      * @return int
-     * @throws coding_exception
      */
-    public function get_lastupdate_answers(object $page, bool $ignoreanswers = false): int {
-        $classname = "\mootimetertool_" . $page->tool . "\\" . $page->tool;
-        if (!class_exists($classname)) {
-            return "Class '" . $page->tool . "' is missing in tool " . $page->tool;
-        }
-
-        $toolhelper = new $classname();
-        if (!method_exists($toolhelper, 'get_last_update_time')) {
-            return "Method 'get_last_update_time' is missing in tools helper class " . $page->tool;
-        }
+    public function get_data_changed(object $page, string $identifier  = '', bool $ignoreanswers = false): int {
 
         $cache = \cache::make('mod_mootimeter', 'lastupdated');
-        $cachekey = 'lastupdate_answers_' . (int) $ignoreanswers . '_' . $page->id;
-        $answerslastupdated = $cache->get($cachekey);
-
-        if (empty($answerslastupdated)) {
-            $answerslastupdated = $toolhelper->get_last_update_time($page->id, $ignoreanswers);
-            $cache->set($cachekey, $answerslastupdated);
-        }
+        $cachekey = 'lastupdate_' . $identifier . '_' . (int) $ignoreanswers . '_' . $page->id;
+        \local_debugger\performance\debugger::print_debug_backtrace('test', 'get data changed_' . $identifier, $cache->get($cachekey));
 
-        return $answerslastupdated;
+        return (int) $cache->get($cachekey);
     }
 
     /**
-     * Get the most recent timestamp of tool settings.
+     * Get the lastupdated timestamp.
      *
-     * @param object $page
-     * @return int
-     * @throws coding_exception
+     * @param int|object $pageorid
+     * @param bool $ignoreanswers
+     * @return mixed
      */
-    public function get_lastupdate_tool_settings(object $page): int {
-        global $DB;
+    public function get_page_last_update_time(
+        int|object $pageorid,
+        string $identifier = '',
+        bool $ignoreanswers = false
+    ): string|int {
 
-        $cache = \cache::make('mod_mootimeter', 'lastupdated');
-        $cachekey = 'lastupdate_settings_' . $page->id;
-        $mostrecenttimesettings = $cache->get($cachekey);
-
-        if (empty($mostrecenttimesettings)) {
-            // Make the settings change test in the global helper class. Because its everywhere the same.
-            // It's important, that the default value is NOT null, but 0 instead. Otherwise GREATEST will return null anyway.
-            $sql = 'SELECT MAX(timemodified) as time FROM {mootimeter_tool_settings} WHERE pageid = :pageid';
-            $record = $DB->get_record_sql($sql, ['pageid' => $page->id]);
-
-            $mostrecenttimesettings = 0;
-            if (!empty($record)) {
-                $mostrecenttimesettings = $record->time;
-            }
+        if (!in_array($identifier, ['settings', 'answers', ''])) {
+            throw new moodle_exception(
+                'generalexceptionmessage',
+                'error',
+                '',
+                get_string("cacheidentifiernotallowed", "mootimeter") . " => " . $identifier
+            );
+        }
+
+        if (is_object($pageorid)) {
+            $page = $pageorid;
+        } else {
+            $page = $this->get_page($pageorid);
+        }
 
-            $mostrecenttimesettings = max($page->timemodified, $page->timecreated, $mostrecenttimesettings);
-            $cache->set($cachekey, $mostrecenttimesettings);
+        // We only want to deliver results if the teacher allowed to view it.
+        $instance = self::get_instance_by_pageid($page->id);
+        $cm = self::get_cm_by_instance($instance);
+        if (
+            empty($this->get_tool_config($page->id, 'showonteacherpermission'))
+            && !has_capability('mod/mootimeter:moderator', \context_module::instance($cm->id))
+        ) {
+            return 0;
+        }
+
+        if (empty($identifier)) {
+            $lastupdatesettings = (int) $this->get_data_changed($page, 'settings');
+            $lastupdateanswers = (int) $this->get_data_changed($page, 'answers', $ignoreanswers);
+            return max($lastupdatesettings, $lastupdateanswers);
         }
 
-        return $mostrecenttimesettings;
+
+        return (int) $this->get_data_changed($page, $identifier, $ignoreanswers);
     }
 
     /**
      * Get the teacherpermission to view state.
      *
-     * @param object $page
+     * @param object|bool $page
      * @return int
      * @throws dml_exception
      * @throws coding_exception
      */
-    public function get_teacherpermission_to_view(object $page): int {
+    public function get_teacherpermission_to_view(object|bool $page): int {
+
+        // On empty page, there are no permissions needed. This is normally the case, if a new page is added.
+        if (empty($page)) {
+            return 0;
+        }
 
         $instance = self::get_instance_by_pageid($page->id);
         $cm = self::get_cm_by_instance($instance);
@@ -1456,13 +1449,6 @@ public function clear_caches(int $pageid): void {
         $cache = \cache::make('mod_mootimeter', 'answers');
         $cache->delete('answers_' . $pageid);
         $cache->delete('cnt_' . $pageid);
-
-        $cache = \cache::make('mod_mootimeter', 'lastupdated');
-        $cache->delete('lastupdate_settings_' . $pageid);
-        // Lastupdate timestamp with answers.
-        $cache->delete('lastupdate_answers_0_' . $pageid);
-        // Lastupdate timestamp without answers.
-        $cache->delete('lastupdate_answers_1_' . $pageid);
     }
 
     /**
diff --git a/classes/local/pagelist.php b/classes/local/pagelist.php
index 0fdfce48..3cb23922 100644
--- a/classes/local/pagelist.php
+++ b/classes/local/pagelist.php
@@ -100,7 +100,7 @@ public function get_pagelist_params(int $cmid, int $pageidselected, object $data
                 'tooltip' => mb_strimwidth($helper::get_tool_config($pagerow, 'question'), 0, 40, '...'),
             ];
 
-            $pageupdatedat = $helper->get_lastupdate_tool_settings($pagerow);
+            $pageupdatedat = $helper->get_page_last_update_time($temppages['pageid'], 'settings');
             $maxtimecreated = max($maxtimecreated, $pageupdatedat);
 
             $pagenumber++;
@@ -111,9 +111,9 @@ public function get_pagelist_params(int $cmid, int $pageidselected, object $data
         // We have to distinguish from which page the request comes.
         // We differentiate between the standard content page (question page) and other pages (eg. results and overview page).
         if (empty($dataset->r) && empty($dataset->o)) {
-            $temppages['dataset']['contentchangedat'] = $helper->get_page_last_update_time($temppages['pageid'], true);
+            $temppages['dataset']['contentchangedat'] = $helper->get_page_last_update_time($temppages['pageid'], '', true);
         } else {
-            $temppages['dataset']['contentchangedat'] = $helper->get_page_last_update_time($temppages['pageid']);
+            $temppages['dataset']['contentchangedat'] = $helper->get_page_last_update_time($temppages['pageid'], '');
         }
         \mod_mootimeter\local\mootimeterstate::add_mootimeterstate('contentchangedat', $temppages['dataset']['contentchangedat']);
 
diff --git a/classes/toolhelper.php b/classes/toolhelper.php
index 26175b6c..4858a256 100644
--- a/classes/toolhelper.php
+++ b/classes/toolhelper.php
@@ -70,15 +70,6 @@ public function get_answer_userid_column(): ?string {
      */
     abstract public function insert_answer(object $page, $answer);
 
-    /**
-     * Get the timestamp of the last answer.
-     *
-     * @param int|object $pageorid
-     * @param bool $ignoreanswers
-     * @return int
-     */
-    abstract public function get_last_update_time(int|object $pageorid, bool $ignoreanswers = false);
-
     /**
      * Delete Page
      *
diff --git a/lang/de/mootimeter.php b/lang/de/mootimeter.php
index 0e7857f9..75119da8 100644
--- a/lang/de/mootimeter.php
+++ b/lang/de/mootimeter.php
@@ -31,6 +31,7 @@
 $string['anonymousmode'] = 'Anonymer Modus';
 $string['anonymousmode_desc'] = ' - Dieses Setting kann nicht verändert werden, sobald Antworten existieren';
 $string['cachedef_answers'] = 'Enthält die Antworten für die Seiten.';
+$string['cacheidentifiernotallowed'] = 'Der verwendete Cache Identifier ist hier nicht zulässig.';
 $string['cannotview'] = 'Sie haben keine Berechtigung, auf diese Seite zuzugreifen!';
 $string['createnewpagesettings'] = 'Neue Seiteneinstellungen';
 $string['default_new_page_visibility'] = 'Neue Seiten standardmäßig sichtbar';
diff --git a/lang/en/mootimeter.php b/lang/en/mootimeter.php
index 79599aa1..7f8314c0 100644
--- a/lang/en/mootimeter.php
+++ b/lang/en/mootimeter.php
@@ -31,6 +31,7 @@
 $string['anonymousmode'] = 'If checked, teachers can not view voters names.';
 $string['anonymousmode_desc'] = 'This setting can not be changed when answers exist!';
 $string['cachedef_answers'] = 'Contains the pages answers.';
+$string['cacheidentifiernotallowed'] = 'The used cache identifier is not allowed here.';
 $string['cannotview'] = 'You are not allowed to access this page!';
 $string['createnewpagesettings'] = 'New page settings';
 $string['default_new_page_visibility'] = 'New pages visible by default';
diff --git a/tools/quiz/classes/quiz.php b/tools/quiz/classes/quiz.php
index 4cb8ef5d..97e6c7f3 100644
--- a/tools/quiz/classes/quiz.php
+++ b/tools/quiz/classes/quiz.php
@@ -773,7 +773,7 @@ public function get_result_params_chartjs(int|object $pageorid): array {
             'labels' => json_encode($labels),
             'values' => json_encode($values),
             'question' => self::get_tool_config($page, 'question'),
-            'lastupdated' =>  $this->get_page_last_update_time($page->id),
+            'lastupdated' =>  $this->get_page_last_update_time($page->id, ''),
             'teacherpermissiontoview' => $this->get_teacherpermission_to_view($page),
         ];
 
@@ -827,40 +827,6 @@ public function delete_answers_tool(object $page, array $conditions): void {
         $this->clear_caches($page->id);
     }
 
-    /**
-     * Get the lastupdated timestamp.
-     *
-     * @param int|object $pageorid
-     * @param bool $ignoreanswers
-     * @return int
-     */
-    public function get_last_update_time(int|object $pageorid, bool $ignoreanswers = false): int {
-        global $DB;
-
-        $page = $pageorid;
-        if (!is_object($page)) {
-            $page = $this->get_page($page);
-        }
-
-        $mostrecenttimeanswer = 0;
-        if (!$ignoreanswers) {
-            // It's important, that the default value is NOT null, but 0 instead. Otherwise GREATEST will return null anyway.
-            $sql = 'SELECT SUM(GREATEST(timecreated, timemodified)) as time FROM '
-                . '{' . $this->get_answer_table() . '} WHERE pageid = :pageid';
-            $queryresultanswer = $DB->get_field_sql($sql, ['pageid' => $page->id]);
-            $mostrecenttimeanswer = !is_null($queryresultanswer) ? $queryresultanswer : 0;
-        }
-
-        // It's important, that the default value is NOT null, but 0 instead. Otherwise GREATEST will return null anyway.
-        $mostrecenttimeoptions = 0;
-        $sql = 'SELECT SUM(GREATEST(timecreated, timemodified)) as time FROM '
-            . '{' . $this->get_answer_option_table() . '} WHERE pageid = :pageid';
-        $queryresultoptions = $DB->get_field_sql($sql, ['pageid' => $page->id]);
-        $mostrecenttimeoptions = !is_null($queryresultoptions) ? $queryresultoptions : 0;
-
-        return $mostrecenttimeanswer + $mostrecenttimeoptions;
-    }
-
     /**
      * Get array of counted values for each answer/ option.
      * @param int $pageid
diff --git a/tools/wordcloud/classes/external/get_answers.php b/tools/wordcloud/classes/external/get_answers.php
index a69b3d1e..3d34d501 100644
--- a/tools/wordcloud/classes/external/get_answers.php
+++ b/tools/wordcloud/classes/external/get_answers.php
@@ -75,7 +75,7 @@ public static function execute(int $pageid, int $lastupdated): array {
         require_capability('mod/mootimeter:view', $cmcontext);
 
         $wordcloud = new wordcloud();
-        $lastupdatednew = $wordcloud->get_page_last_update_time($pageid);
+        $lastupdatednew = $wordcloud->get_page_last_update_time($pageid, 'answers');
 
         $answerlist = $wordcloud->get_answerlist_wordcloud($pageid);
 
diff --git a/tools/wordcloud/classes/wordcloud.php b/tools/wordcloud/classes/wordcloud.php
index fdf0e43f..18a4337f 100644
--- a/tools/wordcloud/classes/wordcloud.php
+++ b/tools/wordcloud/classes/wordcloud.php
@@ -420,35 +420,6 @@ public function get_col_settings_tool_params(object $page, array $params = []) {
         return $returnparams;
     }
 
-    /**
-     * Get the lastupdated timestamp.
-     *
-     * @param int|object $pageorid
-     * @param bool $ignoreanswers
-     * @return int
-     */
-    public function get_last_update_time(int|object $pageorid, bool $ignoreanswers = false): int {
-        global $DB;
-
-        $page = $pageorid;
-        if (!is_object($page)) {
-            $page = $this->get_page($page);
-        }
-
-        $instance = self::get_instance_by_pageid($page->id);
-        $cm = self::get_cm_by_instance($instance);
-
-        $mostrecenttimeanswer = 0;
-        if (!$ignoreanswers) {
-            $sql = 'SELECT SUM(GREATEST(timecreated, timemodified)) as time FROM '
-                . '{' . self::ANSWER_TABLE . '} WHERE pageid = :pageid';
-            $queryresult = $DB->get_field_sql($sql, ['pageid' => $page->id]);
-            $mostrecenttimeanswer = !is_null($queryresult) ? $queryresult : 0;
-        }
-
-        return $mostrecenttimeanswer;
-    }
-
     /**
      * Delete all DB entries related to a specific page.
      * @param object $page