diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt
index 44a7e245d..e3044aa8c 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt
@@ -1306,6 +1306,9 @@ class EventActivity : SimpleActivity() {
 
         // recreate the event if it was moved in a different CalDAV calendar
         if (mEvent.id != null && oldSource != newSource && oldSource != SOURCE_IMPORTED_ICS) {
+            if (mRepeatInterval > 0 && wasRepeatable) {
+                applyOriginalStartEndTimes()
+            }
             eventsHelper.deleteEvent(mEvent.id!!, true)
             mEvent.id = null
         }
@@ -1386,7 +1389,7 @@ class EventActivity : SimpleActivity() {
                 }
                 EDIT_ALL_OCCURRENCES -> {
                     ensureBackgroundThread {
-                        eventsHelper.addEventRepeatLimit(mEvent.id!!, mEventOccurrenceTS)
+                        applyOriginalStartEndTimes()
                         eventsHelper.updateEvent(mEvent, updateAtCalDAV = true, showToasts = true) {
                             finish()
                         }
@@ -1396,6 +1399,22 @@ class EventActivity : SimpleActivity() {
         }
     }
 
+    private fun applyOriginalStartEndTimes() {
+        // Shift the start and end times of the first (original) event based on the changes made
+        val originalEvent = eventsDB.getEventWithId(mEvent.id!!) ?: return
+        val originalStartTS = originalEvent.startTS
+        val originalEndTS = originalEvent.endTS
+        val oldStartTS = mOriginalStartTS
+        val oldEndTS = mOriginalEndTS
+
+        mEvent.apply {
+            val startTSDelta = oldStartTS - startTS
+            val endTSDelta = oldEndTS - endTS
+            startTS = originalStartTS - startTSDelta
+            endTS = originalEndTS - endTSDelta
+        }
+    }
+
     private fun updateStartTexts() {
         updateStartDateText()
         updateStartTimeText()
diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/TaskActivity.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/TaskActivity.kt
index 9dc569daf..8479b7bf6 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/TaskActivity.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/TaskActivity.kt
@@ -502,7 +502,16 @@ class TaskActivity : SimpleActivity() {
                 }
                 EDIT_ALL_OCCURRENCES -> {
                     ensureBackgroundThread {
-                        eventsHelper.addEventRepeatLimit(mTask.id!!, mTaskOccurrenceTS)
+                        // Shift the start and end times of the first (original) event based on the changes made
+                        val originalEvent = eventsDB.getTaskWithId(mTask.id!!) ?: return@ensureBackgroundThread
+                        val originalStartTS = originalEvent.startTS
+                        val oldStartTS = mOriginalStartTS
+
+                        mTask.apply {
+                            val startTSDelta = oldStartTS - startTS
+                            startTS = originalStartTS - startTSDelta
+                            endTS = startTS
+                        }
                         eventsHelper.updateEvent(mTask, updateAtCalDAV = false, showToasts = true) {
                             finish()
                         }