[scheduler] Fix the event dialog moving untouched dates across timezones

packages/x-scheduler-internals-premium/src/timeline-grid/event/TimelineGridEvent.tsx

@@ -13,13 +13,12 @@ import type {
 } from '@mui/x-scheduler-internals/models';
 import {
   useDraggableEvent,
-  generateOccurrenceFromEvent,
+  useOriginalOccurrence,
   computeElementPositionInCollection,
   dateToTimelineAxisOffsetMs,
 } from '@mui/x-scheduler-internals/internals';
 import type { useElementPositionInCollection } from '@mui/x-scheduler-internals/internals';
 import { useAdapterContext } from '@mui/x-scheduler-internals/use-adapter-context';
-import { schedulerEventSelectors } from '@mui/x-scheduler-internals/scheduler-selectors';
 import { useEventTimelinePremiumStoreContext } from '../../use-event-timeline-premium-store-context';
 import { useTimelineGridEventRowContext } from '../event-row/TimelineGridEventRowContext';
 import { TimelineGridEventCssVars } from './TimelineGridEventCssVars';
@@ -52,6 +51,7 @@ export const TimelineGridEvent = React.forwardRef(function TimelineGridEvent(
     // Internal props
     start,
     end,
+    dataBounds,
     eventId,
     occurrenceKey,
     renderDragPreview,
@@ -88,6 +88,14 @@ export const TimelineGridEvent = React.forwardRef(function TimelineGridEvent(
   );
 
   // Feature hooks
+  const getOriginalOccurrence = useOriginalOccurrence({
+    eventId,
+    occurrenceKey,
+    start,
+    end,
+    dataBounds,
+  });
+
   const getSharedDragData: TimelineGridEventContext['getSharedDragData'] = useStableCallback(
     (input) => {
       // Measured on the axis so it stays consistent with the cursor offsets when a
@@ -96,21 +104,11 @@ export const TimelineGridEvent = React.forwardRef(function TimelineGridEvent(
         -dateToTimelineAxisOffsetMs(adapter, config, start.value),
         0,
       );
-      const event = schedulerEventSelectors.processedEvent(store.state, eventId)!;
-
-      const originalOccurrence = generateOccurrenceFromEvent({
-        event,
-        eventId,
-        occurrenceKey,
-        start,
-        end,
-      });
-
       const offsetInsideRow = getCursorPositionInElementMs({ input, elementRef: ref });
       return {
         eventId,
         occurrenceKey,
-        originalOccurrence,
+        originalOccurrence: getOriginalOccurrence(),
         start: start.value,
         end: end.value,
         initialCursorPositionInEventMs: offsetBeforeRowStart + offsetInsideRow,

packages/x-scheduler-internals/src/calendar-grid/day-event/CalendarGridDayEvent.tsx

@@ -17,16 +17,13 @@ import type {
 } from '../../models';
 import { useAdapterContext } from '../../use-adapter-context';
 import { useCalendarGridDayRowContext } from '../day-row/CalendarGridDayRowContext';
-import {
-  schedulerEventSelectors,
-  schedulerOccurrencePlaceholderSelectors,
-} from '../../scheduler-selectors';
+import { schedulerOccurrencePlaceholderSelectors } from '../../scheduler-selectors';
 import { getCalendarGridHeaderCellId } from '../../internals/utils/accessibility-utils';
 import { CalendarGridDayEventContext } from './CalendarGridDayEventContext';
 import { useEventCalendarStoreContext } from '../../use-event-calendar-store-context';
 import { useCalendarGridDayCellContext } from '../day-cell/CalendarGridDayCellContext';
 import { useCalendarGridRootContext } from '../root/CalendarGridRootContext';
-import { generateOccurrenceFromEvent } from '../../internals/utils/event-utils';
+import { useOriginalOccurrence } from '../../internals/utils/useOriginalOccurrence';
 
 const overflowStateAttributesMapping = {
   startingBeforeEdge: (value: boolean) => (value ? { 'data-starting-before-edge': '' } : null),
@@ -45,6 +42,7 @@ export const CalendarGridDayEvent = React.forwardRef(function CalendarGridDayEve
     // Internal props
     start,
     end,
+    dataBounds,
     eventId,
     occurrenceKey,
     renderDragPreview,
@@ -93,21 +91,19 @@ export const CalendarGridDayEvent = React.forwardRef(function CalendarGridDayEve
     );
   });
 
-  const firstEventOfSeries = schedulerEventSelectors.processedEvent(store.state, eventId)!;
-
-  const originalOccurrence = generateOccurrenceFromEvent({
-    event: firstEventOfSeries,
+  const getOriginalOccurrence = useOriginalOccurrence({
     eventId,
     occurrenceKey,
     start,
     end,
+    dataBounds,
   });
 
   const getSharedDragData: CalendarGridDayEventContext['getSharedDragData'] = useStableCallback(
     () => ({
       eventId,
       occurrenceKey,
-      originalOccurrence,
+      originalOccurrence: getOriginalOccurrence(),
       start: start.value,
       end: end.value,
     }),

packages/x-scheduler-internals/src/calendar-grid/time-event/CalendarGridTimeEvent.tsx

@@ -12,16 +12,14 @@ import { useElementPositionInCollection } from '../../internals/utils/useElement
 import { getCalendarGridHeaderCellId } from '../../internals/utils/accessibility-utils';
 import { CalendarGridTimeEventContext } from './CalendarGridTimeEventContext';
 import { useAdapterContext } from '../../use-adapter-context';
-import { useEventCalendarStoreContext } from '../../use-event-calendar-store-context';
-import { schedulerEventSelectors } from '../../scheduler-selectors';
 import type {
   SchedulerEventId,
   SchedulerEventOccurrence,
   SchedulerResourceId,
   TemporalSupportedObject,
 } from '../../models';
 import { useCalendarGridRootContext } from '../root/CalendarGridRootContext';
-import { generateOccurrenceFromEvent } from '../../internals/utils/event-utils';
+import { useOriginalOccurrence } from '../../internals/utils/useOriginalOccurrence';
 
 export const CalendarGridTimeEvent = React.forwardRef(function CalendarGridTimeEvent(
   componentProps: CalendarGridTimeEvent.Props,
@@ -35,6 +33,7 @@ export const CalendarGridTimeEvent = React.forwardRef(function CalendarGridTimeE
     // Internal props
     start,
     end,
+    dataBounds,
     eventId,
     occurrenceKey,
     renderDragPreview,
@@ -48,7 +47,6 @@ export const CalendarGridTimeEvent = React.forwardRef(function CalendarGridTimeE
 
   // Context hooks
   const adapter = useAdapterContext();
-  const store = useEventCalendarStoreContext();
   const { id: rootId } = useCalendarGridRootContext();
   const {
     start: columnStart,
@@ -67,18 +65,16 @@ export const CalendarGridTimeEvent = React.forwardRef(function CalendarGridTimeE
   const id = useId(idProp);
 
   // Feature hooks
+  const getOriginalOccurrence = useOriginalOccurrence({
+    eventId,
+    occurrenceKey,
+    start,
+    end,
+    dataBounds,
+  });
+
   const getSharedDragData: CalendarGridTimeEventContext['getSharedDragData'] = useStableCallback(
     (input) => {
-      const event = schedulerEventSelectors.processedEvent(store.state, eventId)!;
-
-      const originalOccurrence = generateOccurrenceFromEvent({
-        event,
-        eventId,
-        occurrenceKey,
-        start,
-        end,
-      });
-
       // No `input` (pointer-based resize) — skip the layout-reading cursor measurement.
       const initialCursorPositionInEventMs = input
         ? Math.max(adapter.getTime(columnStart) - start.timestamp, 0) +
@@ -88,7 +84,7 @@ export const CalendarGridTimeEvent = React.forwardRef(function CalendarGridTimeE
       return {
         eventId,
         occurrenceKey,
-        originalOccurrence,
+        originalOccurrence: getOriginalOccurrence(),
         start: start.value,
         end: end.value,
         initialCursorPositionInEventMs,