diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index b0ed531063..fe5aa7aa88 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -1577,8 +1577,10 @@ class calendar_boupdate extends calendar_bo
 			$event['created'] = $save_event['created'] = $this->now;
 			$event['creator'] = $save_event['creator'] = $this->user;
 		}
-		$set_recurrences = $old_event ? abs(Api\DateTime::to($event['recur_enddate'] ?? null, 'utc') - Api\DateTime::to($old_event['recur_enddate'] ?? null, 'utc')) > 1 ||
-			count($old_event['recur_exception'] ?? []) != count($event['recur_exception'] ?? []) : false;
+		$set_recurrences = !$old_event ? false :
+			abs(Api\DateTime::to($event['recur_enddate'] ?? null, 'utc') - Api\DateTime::to($old_event['recur_enddate'] ?? null, 'utc')) > 1 ||
+			count($old_event['recur_exception'] ?? []) != count($event['recur_exception'] ?? []) ||
+			count($old_event['recur_rdates'] ?? []) != count($event['recur_rdates'] ?? []);
 		$set_recurrences_start = 0;
 		if (($cal_id = $this->so->save($event,$set_recurrences,$set_recurrences_start,0,$event['etag'])) && $set_recurrences && !empty($event['recur_type']))
 		{
diff --git a/calendar/inc/class.calendar_uiforms.inc.php b/calendar/inc/class.calendar_uiforms.inc.php
index 5f4545eca4..35837a0d31 100644
--- a/calendar/inc/class.calendar_uiforms.inc.php
+++ b/calendar/inc/class.calendar_uiforms.inc.php
@@ -344,8 +344,17 @@ class calendar_uiforms extends calendar_ui
 			unset($content['recur_rdates']['delete_rdate']);
 			if (($key = array_search($date, $content['recur_rdates'])) !== false)
 			{
-				unset($content['recur_rdates'][$key]);
-				$content['recur_rdates'] = array_values($content['recur_rdates']);
+				// if this is an initial edit, simply remove the rdate
+				if (empty($content['id']))
+				{
+					unset($content['recur_rdates'][$key]);
+					$content['recur_rdates'] = array_values($content['recur_rdates']);
+				}
+				// otherwise add the recurrence as (deleted) exception
+				elseif (!in_array($date, $content['recur_exception']))
+				{
+					$content['recur_exception'][] = $date;
+				}
 			}
 		}
 		// delete an alarm
diff --git a/calendar/js/app.ts b/calendar/js/app.ts
index 56da6bf188..c934332210 100644
--- a/calendar/js/app.ts
+++ b/calendar/js/app.ts
@@ -317,7 +317,7 @@ export class CalendarApp extends EgwApp
 					{
 						this.freetime_search();
 					}
-					//send Syncronus ajax request to the server to unlock the on close entry
+					//send synchronous ajax request to the server to unlock the on close entry
 					//set onbeforeunload with json request to send request when the window gets close by X button
 					if (content.data.lock_token)
 					{
@@ -1421,6 +1421,7 @@ export class CalendarApp extends EgwApp
 		{
 			addRdate.set_disabled(recurType.value != 9);
 			recurRdate.set_disabled(recurType.value != 9);
+			this.et2.getWidgetById('recur_enddate')?.set_disabled(recurType.value == 9);
 		}
 	}
 
diff --git a/calendar/lang/egw_de.lang b/calendar/lang/egw_de.lang
index f4bba6d119..cf73c18e3d 100644
--- a/calendar/lang/egw_de.lang
+++ b/calendar/lang/egw_de.lang
@@ -36,6 +36,7 @@ add recurrence	calendar	de	Wiederholung hinzufügen
 add timesheet entry	calendar	de	Stundenzettel hinzufügen
 added	calendar	de	Neuer Termin
 added by synchronization	calendar	de	Durch Synchronisation hinzugefügt
+added recurrence on %1.	calendar	de	Wiederholung am %1 hinzugefügt.
 after	calendar	de	Nach
 after %1	calendar	de	Nach dem %1
 after current date	calendar	de	Nach dem aktuellen Datum
diff --git a/calendar/lang/egw_en.lang b/calendar/lang/egw_en.lang
index 5b68e1f494..45b28b7d1c 100644
--- a/calendar/lang/egw_en.lang
+++ b/calendar/lang/egw_en.lang
@@ -36,6 +36,7 @@ add recurrence	calendar	en	Add recurrence
 add timesheet entry	calendar	en	Add timesheet entry
 added	calendar	en	Added
 added by synchronization	calendar	en	Added by synchronization
+added recurrence on %1.	calendar	en	Added recurrence on %1.
 after	calendar	en	After
 after %1	calendar	en	After %1
 after current date	calendar	en	After current date