diff --git a/src/mixins/EditorMixin.js b/src/mixins/EditorMixin.js
index d334ab7dc..7a856c69d 100644
--- a/src/mixins/EditorMixin.js
+++ b/src/mixins/EditorMixin.js
@@ -587,6 +587,8 @@ export default {
 			this.calendarObjectInstanceStore.changeStartDate({
 				calendarObjectInstance: this.calendarObjectInstance,
 				startDate,
+				onlyTime: false,
+				changeEndDate: false,
 			})
 		},
 		/**
diff --git a/src/store/calendarObjectInstance.js b/src/store/calendarObjectInstance.js
index 0d00c43ea..d3881c452 100644
--- a/src/store/calendarObjectInstance.js
+++ b/src/store/calendarObjectInstance.js
@@ -1529,15 +1529,12 @@ export default defineStore('calendarObjectInstance', {
 			calendarObjectInstance,
 			startDate,
 			onlyTime = false,
+			changeEndDate = true,
 		}) {
 			if (onlyTime) {
 				startDate.setFullYear(calendarObjectInstance.startDate.getFullYear(), calendarObjectInstance.startDate.getMonth(), calendarObjectInstance.startDate.getDate())
 			}
 
-			if (!onlyTime) {
-				startDate.setHours(calendarObjectInstance.startDate.getHours(), calendarObjectInstance.startDate.getMinutes(), calendarObjectInstance.startDate.getSeconds())
-			}
-
 			const difference = startDate.getTime() - calendarObjectInstance.startDate.getTime()
 			const endDate = new Date(calendarObjectInstance.endDate.getTime() + difference)
 
@@ -1545,10 +1542,13 @@ export default defineStore('calendarObjectInstance', {
 				calendarObjectInstance,
 				startDate,
 			})
-			this.changeEndDateMutation({
-				calendarObjectInstance,
-				endDate,
-			})
+
+			if (changeEndDate) {
+				this.changeEndDateMutation({
+					calendarObjectInstance,
+					endDate,
+				})
+			}
 		},
 
 		/**
@@ -1591,10 +1591,6 @@ export default defineStore('calendarObjectInstance', {
 				endDate.setFullYear(calendarObjectInstance.endDate.getFullYear(), calendarObjectInstance.endDate.getMonth(), calendarObjectInstance.endDate.getDate())
 			}
 
-			if (!onlyTime) {
-				endDate.setHours(calendarObjectInstance.endDate.getHours(), calendarObjectInstance.endDate.getMinutes(), calendarObjectInstance.endDate.getSeconds())
-			}
-
 			this.changeEndDateMutation({
 				calendarObjectInstance,
 				endDate,