diff --git a/src/components/events/partials/ModalTabsAndPages/NewSourcePage.tsx b/src/components/events/partials/ModalTabsAndPages/NewSourcePage.tsx
index c6c117b124..2bfedc4ae3 100644
--- a/src/components/events/partials/ModalTabsAndPages/NewSourcePage.tsx
+++ b/src/components/events/partials/ModalTabsAndPages/NewSourcePage.tsx
@@ -370,6 +370,60 @@ const Schedule = <T extends {
 }) => {
 	const { t } = useTranslation();
 	const currentLanguage = getCurrentLanguageInformation();
+	const getEndDateForSchedulingTime = () => {
+		const {
+			scheduleStartDate,
+			scheduleStartHour,
+			scheduleStartMinute,
+			scheduleEndDate,
+			scheduleEndHour,
+			scheduleEndMinute,
+			scheduleDurationHours,
+			sourceMode,
+		} = formik.values;
+
+		const durationHours = Number(scheduleDurationHours) || 0;
+
+		if (durationHours === 0) {
+			return undefined;
+		}
+
+		const startDateTime = new Date(scheduleStartDate);
+		startDateTime.setHours(
+			parseInt(scheduleStartHour, 10),
+			parseInt(scheduleStartMinute, 10),
+			0,
+			0,
+		);
+
+		let endDateTime: Date;
+
+		if (sourceMode === "SCHEDULE_MULTIPLE") {
+			endDateTime = new Date(startDateTime);
+			endDateTime.setHours(endDateTime.getHours() + durationHours);
+		} else {
+			if (!scheduleEndDate) {
+				return undefined;
+			}
+			endDateTime = new Date(scheduleEndDate);
+			endDateTime.setHours(
+				parseInt(scheduleEndHour, 10),
+				parseInt(scheduleEndMinute, 10),
+				0,
+				0,
+			);
+		}
+
+		if (
+			endDateTime.getDate() !== startDateTime.getDate() ||
+			endDateTime.getMonth() !== startDateTime.getMonth() ||
+			endDateTime.getFullYear() !== startDateTime.getFullYear()
+		) {
+			return "+1 day";
+		}
+		return undefined;
+	};
+
 
 	const renderInputDeviceOptions = () => {
 		if (formik.values.location) {
@@ -606,13 +660,7 @@ const Schedule = <T extends {
 									);
 								}
 							}}
-							date={
-								formik.values.sourceMode === "SCHEDULE_SINGLE" &&
-								(new Date(formik.values.scheduleEndDate).getDate() !==
-								new Date(formik.values.scheduleStartDate).getDate())
-								? formik.values.scheduleEndDate
-								: undefined
-							}
+							date={getEndDateForSchedulingTime()}
 						/>
 
 						<SchedulingLocation
diff --git a/src/components/events/partials/wizards/scheduling/SchedulingTime.tsx b/src/components/events/partials/wizards/scheduling/SchedulingTime.tsx
index 46ad6fbe77..f7ba97fe48 100644
--- a/src/components/events/partials/wizards/scheduling/SchedulingTime.tsx
+++ b/src/components/events/partials/wizards/scheduling/SchedulingTime.tsx
@@ -69,16 +69,20 @@ const SchedulingTime = ({
 					disabled={disabled}
 					customCSS={{ width: 70 }}
 				/>
-
 				{/* Displays given date. Can be used to signify which date the
 				  scheduling time belong to*/}
-				{date &&
+				{date && (
 					<span style={{ marginLeft: "10px" }}>
-						{new Date(date).toLocaleDateString(
-							currentLanguage ? currentLanguage.dateLocale.code : undefined,
-						)}
+						{typeof date === "string"
+							? date // show the string as it is
+							: date instanceof Date && !isNaN(date.getDate())
+							? new Date(date).toLocaleDateString(
+									currentLanguage ? currentLanguage.dateLocale.code : undefined,
+								)
+							: null
+						}
 					</span>
-				}
+				)}
 			</td>
 		</tr>
 	);
diff --git a/src/i18n/org/opencastproject/adminui/languages/lang-en_US.json b/src/i18n/org/opencastproject/adminui/languages/lang-en_US.json
index 028706ce3c..4b2843ff91 100644
--- a/src/i18n/org/opencastproject/adminui/languages/lang-en_US.json
+++ b/src/i18n/org/opencastproject/adminui/languages/lang-en_US.json
@@ -211,6 +211,7 @@
 		"CONFLICT_ALREADY_ENDED": "Scheduling error: The event has already ended.",
 		"CONFLICT_END_BEFORE_START": "Scheduling error: Schedule end has to be later than the start.",
 		"CONFLICT_IN_THE_PAST": "The schedule could not be updated: You cannot schedule an event to be in the past.",
+		"CONFLICT_RANGE_DAYS":"At least one repeat day must be within the scheduled date range.",
 		"INVALID_ACL_RULES": "Rules have to contain a valid role and read or/and write right(s).",
 		"MISSING_ACL_RULES": "At least one role with Read and Write permissions is required!",
 		"SAVED_ACL_RULES": "The access rules have been saved.",
diff --git a/src/slices/eventSlice.ts b/src/slices/eventSlice.ts
index 30a1a31d14..baa4a318bc 100644
--- a/src/slices/eventSlice.ts
+++ b/src/slices/eventSlice.ts
@@ -910,6 +910,20 @@ export const checkConflicts = (values: {
 		values.sourceMode === "SCHEDULE_SINGLE" ||
 		values.sourceMode === "SCHEDULE_MULTIPLE"
 	) {
+			if (values.sourceMode === "SCHEDULE_MULTIPLE") {
+				const isRepeatOnValid = validateRepeatOnInRange(values);
+				if (!isRepeatOnValid) {
+					dispatch(
+						addNotification({
+						type: "error",
+						key: "CONFLICT_RANGE_DAYS",
+						duration: -1,
+						context: NOTIFICATION_CONTEXT,
+						}),
+					);
+				return false; // Exit early if repeatOn is invalid
+			}
+		}
 		// Get timezone offset; Checks should be performed on UTC times
 		// let offset = getTimezoneOffset();
 
@@ -924,7 +938,7 @@ export const checkConflicts = (values: {
 		);
 
 		// If start date of event is smaller than today --> Event is in past
-		if (values.sourceMode === "SCHEDULE_SINGLE" && startDate < new Date()) {
+		if ((values.sourceMode === "SCHEDULE_SINGLE" && startDate < new Date()) || (values.sourceMode === "SCHEDULE_MULTIPLE" && startDate < new Date())) {
 			dispatch(
 				addNotification({
 					type: "error",
@@ -1107,6 +1121,42 @@ export const checkForSchedulingConflicts = (events: EditedEvents[]) => (dispatch
 	return data;
 };
 
+export const validateRepeatOnInRange = (values: {
+	repeatOn: string[],           // e.g. ["MO", "TU"]
+	scheduleStartDate: string,    // e.g. "2025-08-11"
+	scheduleEndDate: string       // e.g. "2025-08-13"
+}) => {
+	if (!values.repeatOn || values.repeatOn.length === 0) {
+		return true;
+	}
+
+	const start = new Date(values.scheduleStartDate);
+	const end = new Date(values.scheduleEndDate);
+
+	// Map day codes to numbers: Sunday=0, Monday=1, ..., Saturday=6
+	const dayMap: Record<string, number> = {
+		SU: 0,
+		MO: 1,
+		TU: 2,
+		WE: 3,
+		TH: 4,
+		FR: 5,
+		SA: 6,
+	};
+	const repeatDays = values.repeatOn.map(day => dayMap[day]);
+	// Check if **at least one** date in the [start..end] range matches repeatOn days
+	const current = new Date(start);
+	while (current <= end) {
+		if (repeatDays.includes(current.getDay())) {
+			return true;  // Valid because this repeat day is in range
+		}
+		current.setDate(current.getDate() + 1); // next day
+	}
+
+	// If no repeat days fall within the range, return false
+	return false;
+};
+
 const eventSlice = createSlice({
 	name: "events",
 	initialState,