diff --git a/components/ILIAS/Calendar/classes/Export/class.ilCalendarExport.php b/components/ILIAS/Calendar/classes/Export/class.ilCalendarExport.php
index cb3793697c02..f1da2893c122 100755
--- a/components/ILIAS/Calendar/classes/Export/class.ilCalendarExport.php
+++ b/components/ILIAS/Calendar/classes/Export/class.ilCalendarExport.php
@@ -306,7 +306,7 @@ protected function createRecurrences(ilCalendarEntry $app): ilICalWriter
         $str_writer = new ilICalWriter();
         foreach (ilCalendarRecurrences::_getRecurrences($app->getEntryId()) as $rec) {
             foreach (ilCalendarRecurrenceExclusions::getExclusionDates($app->getEntryId()) as $excl) {
-                $str_writer->addLine($excl->toICal());
+                $str_writer->addLine($excl->toICal($this->il_user->getTimeZone()));
             }
             $recurrence_ical = $rec->toICal($this->il_user->getId());
             if (strlen($recurrence_ical)) {
diff --git a/components/ILIAS/Calendar/classes/class.ilCalendarRecurrence.php b/components/ILIAS/Calendar/classes/class.ilCalendarRecurrence.php
index c847c08648ca..f41f214075c5 100755
--- a/components/ILIAS/Calendar/classes/class.ilCalendarRecurrence.php
+++ b/components/ILIAS/Calendar/classes/class.ilCalendarRecurrence.php
@@ -106,8 +106,13 @@ public function toICal(int $a_user_id): string
             if ($entry->isFullday()) {
                 $ical .= (';UNTIL=' . $this->getFrequenceUntilDate()->get(IL_CAL_FKT_DATE, 'Ymd'));
             } else {
-                $his = $entry->getStart()->get(IL_CAL_FKT_DATE, 'His');
-                $ical .= (';UNTIL=' . $this->getFrequenceUntilDate()->get(IL_CAL_FKT_DATE, 'Ymd') . 'T' . $his);
+                $user = new ilObjUser($a_user_id);
+                $tz = $user->getTimeZone();
+                $local_time = $entry->getStart()->get(IL_CAL_FKT_DATE, 'H:i:s', $tz);
+                $until_date = $this->getFrequenceUntilDate()->get(IL_CAL_FKT_DATE, 'Y-m-d');
+                $until_dt = new ilDateTime($until_date . ' ' . $local_time, IL_CAL_DATETIME, $tz);
+                $ical .= ';UNTIL=' . $until_dt->get(IL_CAL_FKT_DATE, 'Ymd', ilTimeZone::UTC) .
+                         'T' . $until_dt->get(IL_CAL_FKT_DATE, 'His', ilTimeZone::UTC) . 'Z';
             }
         }
         if ($this->getBYMONTH()) {
diff --git a/components/ILIAS/Calendar/classes/class.ilCalendarRecurrenceExclusion.php b/components/ILIAS/Calendar/classes/class.ilCalendarRecurrenceExclusion.php
index 54361e1037c3..1ac742b64eef 100755
--- a/components/ILIAS/Calendar/classes/class.ilCalendarRecurrenceExclusion.php
+++ b/components/ILIAS/Calendar/classes/class.ilCalendarRecurrenceExclusion.php
@@ -67,7 +67,7 @@ public function setDate(?ilDate $dt = null): void
         $this->exclusion = $dt;
     }
 
-    public function toICal(): string
+    public function toICal(string $a_tz = ''): string
     {
         $entry = new ilCalendarEntry($this->getEntryId());
         $start = $entry->getStart();
@@ -75,9 +75,13 @@ public function toICal(): string
         if ($entry->isFullday()) {
             return 'EXDATE;VALUE=DATE:' . $this->getDate()->get(IL_CAL_FKT_DATE, 'Ymd');
         } else {
+            $tz = $a_tz ?: ilTimeZone::UTC;
+            $local_time = $start->get(IL_CAL_FKT_DATE, 'H:i:s', $tz);
+            $excl_date = $this->getDate()->get(IL_CAL_FKT_DATE, 'Y-m-d');
+            $excl_dt = new ilDateTime($excl_date . ' ' . $local_time, IL_CAL_DATETIME, $tz);
             return 'EXDATE:' .
-                $this->getDate()->get(IL_CAL_FKT_DATE, 'Ymd', ilTimeZone::UTC) .
-                'T' . $start->get(IL_CAL_FKT_DATE, 'His', ilTimeZone::UTC) . 'Z';
+                $excl_dt->get(IL_CAL_FKT_DATE, 'Ymd', ilTimeZone::UTC) .
+                'T' . $excl_dt->get(IL_CAL_FKT_DATE, 'His', ilTimeZone::UTC) . 'Z';
         }
     }