diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.css b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.css
new file mode 100644
index 000000000000..cd972b089814
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.css
@@ -0,0 +1,67 @@
+::ng-deep .dx-scheduler-appointment {
+  color: #242424;
+}
+
+.options {
+  padding: 20px;
+  background-color: rgba(191, 191, 191, 0.15);
+  margin-top: 20px;
+}
+
+.option {
+  margin-top: 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+::ng-deep .dx-item:has(.conflict-informer[hidden]) {
+  display: none !important;
+}
+
+::ng-deep .conflict-informer {
+  background-color: #FCEAE8;
+  color: #C50F1F;
+  font-size: 12px;
+  padding: 0 12px;
+  height: 36px;
+  line-height: 36px;
+  box-sizing: border-box;
+  margin-bottom: 8px;
+}
+
+::ng-deep .dx-dialog:has(#conflict-dialog) .dx-overlay-content {
+  width: 280px;
+}
+
+::ng-deep .dx-dialog:has(#conflict-dialog) .dx-dialog-content {
+  padding-bottom: 16px;
+}
+
+::ng-deep .dx-dialog:has(#conflict-dialog) .dx-dialog-buttons {
+  padding-top: 0;
+  padding-bottom: 16px;
+}
+
+::ng-deep .dx-dialog:has(#conflict-dialog) .dx-toolbar-center,
+::ng-deep .dx-dialog:has(#conflict-dialog) .dx-button {
+  width: 100%;
+}
+
+::ng-deep .dx-scheduler-form-main-group .dx-item:last-child,
+::ng-deep .dx-scheduler-form-main-group .dx-item:last-child .dx-field-item-content,
+::ng-deep .dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child,
+::ng-deep .dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child .dx-field-item-content {
+  overflow: visible;
+}
+
+::ng-deep #form .dx-scheduler-form-main-group,
+::ng-deep #form .dx-scheduler-form-recurrence-group {
+  padding-top: 0;
+}
+
+::ng-deep #form:has(.conflict-informer:not([hidden])) .dx-scheduler-form-recurrence-group.dx-scheduler-form-recurrence-group-hidden,
+::ng-deep #form:has(.conflict-informer:not([hidden])) .dx-scheduler-form-main-group.dx-scheduler-form-main-group-hidden {
+  top: 44px;
+}
+
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.html
new file mode 100644
index 000000000000..78d0e227ca28
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.html
@@ -0,0 +1,78 @@
+<dx-scheduler
+  [dataSource]="appointmentsData"
+  [views]="views"
+  currentView="week"
+  [startDayHour]="9"
+  [endDayHour]="19"
+  [currentDate]="currentDate"
+  [height]="600"
+  [showAllDayPanel]="false"
+  allDayPanelMode="hidden"
+  (onAppointmentAdding)="onAppointmentAdding($event)"
+  (onAppointmentUpdating)="onAppointmentUpdating($event)"
+>
+  <dxi-scheduler-resource
+    fieldExpr="assigneeId"
+    [dataSource]="assignees"
+    valueExpr="id"
+    colorExpr="color"
+    icon="user"
+    [allowMultiple]="true"
+  ></dxi-scheduler-resource>
+
+  <dxo-scheduler-editing [popup]="popupOptions">
+    <dxo-scheduler-form
+      labelMode="hidden"
+      [elementAttr]="formElementAttr"
+      [customizeItem]="customizeItem"
+      (onInitialized)="onFormInitialized($event)"
+    >
+      <dxi-scheduler-item
+        name="conflictInformer"
+        template="conflictInformerTemplate"
+      ></dxi-scheduler-item>
+      <dxi-scheduler-item name="mainGroup" itemType="group">
+        <dxi-scheduler-item name="subjectGroup"></dxi-scheduler-item>
+        <dxi-scheduler-item name="dateGroup"></dxi-scheduler-item>
+        <dxi-scheduler-item name="repeatGroup"></dxi-scheduler-item>
+        <dxi-scheduler-item name="assigneeIdGroup">
+          <dxi-scheduler-item name="assigneeIdIcon"></dxi-scheduler-item>
+          <dxi-scheduler-item
+            name="assigneeId"
+            [isRequired]="true"
+            [editorOptions]="assigneeIdEditorOptions"
+          ></dxi-scheduler-item>
+        </dxi-scheduler-item>
+      </dxi-scheduler-item>
+      <dxi-scheduler-item name="recurrenceGroup" itemType="group"></dxi-scheduler-item>
+    </dxo-scheduler-form>
+  </dxo-scheduler-editing>
+
+  <div *dxTemplate="let _ of 'conflictInformerTemplate'">
+    <div class="conflict-informer" [hidden]="!showConflictError">This time slot conflicts with another appointment.</div>
+  </div>
+
+  <div *dxTemplate="let tagData of 'assigneeTagTemplate'">
+    <div
+      class="dx-tag-content"
+      [style.background-color]="tagData.color"
+      [style.border-color]="tagData.color"
+    >
+      <span>{{ tagData.text }}</span>
+      <div class="dx-tag-remove-button"></div>
+    </div>
+  </div>
+</dx-scheduler>
+<div class="options">
+  <div class="option">
+    <span>Overlapping Rule</span>
+    <dx-select-box
+      [items]="overlappingRuleItems"
+      valueExpr="value"
+      displayExpr="text"
+      value="sameResource"
+      [width]="200"
+      (onValueChanged)="onOverlappingRuleChanged($event)"
+    ></dx-select-box>
+  </div>
+</div>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.ts b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.ts
new file mode 100644
index 000000000000..b9c657011c47
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.component.ts
@@ -0,0 +1,213 @@
+import { bootstrapApplication } from '@angular/platform-browser';
+import { Component, enableProdMode, provideZoneChangeDetection } from '@angular/core';
+import { DxSchedulerModule, DxSelectBoxModule, DxTemplateModule } from 'devextreme-angular';
+import { DxSchedulerTypes } from 'devextreme-angular/ui/scheduler';
+import { DxSelectBoxTypes } from 'devextreme-angular/ui/select-box';
+import { DxFormTypes } from 'devextreme-angular/ui/form';
+import { DxPopupTypes } from 'devextreme-angular/ui/popup';
+import { custom as customDialog } from 'devextreme/ui/dialog';
+import { Appointment, Assignee, Service, assignees } from './app.service';
+
+type dxScheduler = NonNullable<DxSchedulerTypes.InitializedEvent['component']>;
+type dxForm = NonNullable<DxFormTypes.InitializedEvent['component']>;
+type dxPopup = NonNullable<DxPopupTypes.InitializedEvent['component']>;
+
+if (!/localhost/.test(document.location.host)) {
+  enableProdMode();
+}
+
+let modulePrefix = '';
+// @ts-ignore
+if (window && window.config?.packageConfigPaths) {
+  modulePrefix = '/app';
+}
+
+@Component({
+  selector: 'demo-app',
+  templateUrl: `.${modulePrefix}/app.component.html`,
+  styleUrls: [`.${modulePrefix}/app.component.css`],
+  providers: [Service],
+  preserveWhitespaces: true,
+  imports: [
+    DxSchedulerModule,
+    DxSelectBoxModule,
+    DxTemplateModule,
+  ],
+})
+export class AppComponent {
+  appointmentsData: Appointment[];
+
+  currentDate: Date = new Date(2026, 1, 10);
+
+  views: DxSchedulerTypes.ViewType[] = ['day', 'week', 'workWeek', 'month'];
+
+  assignees: Assignee[] = assignees;
+
+  overlappingRuleItems = [
+    { value: 'sameResource', text: 'Allow across resources' },
+    { value: 'allResources', text: 'Disallow all overlaps' },
+  ];
+
+  assigneeIdEditorOptions = {
+    onValueChanged: (e: { value: unknown[]; component: { option: (k: string, v: unknown) => void } }) => {
+      if (e.value.length > 1) {
+        e.component.option('value', [e.value[e.value.length - 1]]);
+      }
+    },
+    tagTemplate: 'assigneeTagTemplate',
+  };
+
+  popupOptions = {
+    onInitialized: (e: { component: dxPopup }) => { this.popup = e.component; },
+    onHidden: () => {
+      this.setConflictError(false);
+      this.form?.updateData('assigneeId', []);
+    },
+  };
+
+  formElementAttr = { id: 'form' };
+
+  private popup?: dxPopup;
+
+  private form?: dxForm;
+
+  showConflictError = false;
+
+  private overlappingRule = 'sameResource';
+
+  constructor(service: Service) {
+    this.appointmentsData = service.getAppointments();
+  }
+
+  setConflictError(show: boolean): void {
+    this.showConflictError = show;
+  }
+
+  onFormInitialized(e: DxFormTypes.InitializedEvent): void {
+    this.form = e.component;
+    this.form.on('fieldDataChanged', (event: { dataField: string }) => {
+      if (this.showConflictError && ['startDate', 'endDate', 'assigneeId', 'recurrenceRule'].includes(event.dataField)) {
+        this.setConflictError(false);
+        this.form.validate();
+      }
+    });
+  }
+
+  customizeItem = (item: DxFormTypes.SimpleItem): void => {
+    if (item.name === 'allDayEditor' || item.name === 'recurrenceEndEditor') {
+      item.label.visible = true;
+    } else if (item.name === 'subjectEditor') {
+      item.editorOptions = item.editorOptions || {};
+      item.editorOptions.placeholder = 'Add title';
+    }
+
+    if (item.name === 'startTimeEditor' || item.name === 'endTimeEditor') {
+      item.validationRules = [
+        { type: 'required' },
+        {
+          type: 'custom',
+          message: 'Time conflict',
+          ignoreEmptyValue: true,
+          reevaluate: true,
+          validationCallback: () => !this.showConflictError,
+        },
+      ];
+    }
+  };
+
+  private getNextDay(date: Date): Date {
+    const next = new Date(date);
+    next.setDate(next.getDate() + 1);
+    return next;
+  }
+
+  private getEndDate(occurrence: DxSchedulerTypes.Occurrence): Date {
+    return (occurrence.appointmentData as Appointment).allDay
+      ? this.getNextDay(occurrence.startDate)
+      : occurrence.endDate;
+  }
+
+  private isOverlapping(a: DxSchedulerTypes.Occurrence, b: DxSchedulerTypes.Occurrence): boolean {
+    const aEnd = this.getEndDate(a);
+    const bEnd = this.getEndDate(b);
+    if (a.startDate >= bEnd || b.startDate >= aEnd) return false;
+    if (this.overlappingRule === 'sameResource') {
+      return (a.appointmentData as Appointment).assigneeId[0] === (b.appointmentData as Appointment).assigneeId[0];
+    }
+    return true;
+  }
+
+  private detectConflict(scheduler: dxScheduler, newAppointment: Appointment): boolean {
+    const allAppointments = scheduler.getDataSource().items() as Appointment[];
+    const startDate = new Date(newAppointment.startDate);
+    let endDate: Date;
+    if (newAppointment.recurrenceRule) {
+      endDate = scheduler.getEndViewDate();
+    } else if (newAppointment.allDay) {
+      endDate = this.getNextDay(startDate);
+    } else {
+      endDate = new Date(newAppointment.endDate);
+    }
+
+    const existingOccurrences = scheduler
+      .getOccurrences(startDate, endDate, allAppointments)
+      .filter((occurrence) => (occurrence.appointmentData as Appointment).id !== newAppointment.id);
+
+    const newOccurrences = scheduler.getOccurrences(startDate, endDate, [newAppointment]);
+
+    return newOccurrences.some((newOccurrence) =>
+      existingOccurrences.some((existingOccurrence) =>
+        this.isOverlapping(newOccurrence, existingOccurrence),
+      ),
+    );
+  }
+
+  private alertConflictIfNeeded(
+    e: DxSchedulerTypes.AppointmentAddingEvent | DxSchedulerTypes.AppointmentUpdatingEvent,
+    appointmentData: Appointment,
+  ): void {
+    if (!this.detectConflict(e.component, appointmentData)) {
+      this.setConflictError(false);
+      return;
+    }
+
+    e.cancel = true;
+
+    if (this.popup?.option('visible')) {
+      this.setConflictError(true);
+      this.form?.validate();
+    } else {
+      const dialog = customDialog({
+        showTitle: false,
+        messageHtml: '<p id="conflict-dialog">This time slot conflicts with another appointment.</p>',
+        buttons: [{
+          type: 'default',
+          text: 'Close',
+          stylingMode: 'contained',
+          onClick: () => {
+            dialog.hide();
+          },
+        }],
+      });
+      dialog.show();
+    }
+  }
+
+  onAppointmentAdding(e: DxSchedulerTypes.AppointmentAddingEvent): void {
+    this.alertConflictIfNeeded(e, e.appointmentData as Appointment);
+  }
+
+  onAppointmentUpdating(e: DxSchedulerTypes.AppointmentUpdatingEvent): void {
+    this.alertConflictIfNeeded(e, { ...e.oldData, ...e.newData } as Appointment);
+  }
+
+  onOverlappingRuleChanged(e: DxSelectBoxTypes.ValueChangedEvent): void {
+    this.overlappingRule = e.value;
+  }
+}
+
+bootstrapApplication(AppComponent, {
+  providers: [
+    provideZoneChangeDetection({ eventCoalescing: true, runCoalescing: true }),
+  ],
+});
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.service.ts b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.service.ts
new file mode 100644
index 000000000000..ee832f63b345
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/app/app.service.ts
@@ -0,0 +1,111 @@
+import { Injectable } from '@angular/core';
+
+export interface Appointment {
+  id: number;
+  text: string;
+  startDate: Date;
+  endDate: Date;
+  assigneeId: number[];
+  recurrenceRule?: string;
+  allDay?: boolean;
+}
+
+export interface Assignee {
+  id: number;
+  text: string;
+  color: string;
+}
+
+export const assignees: Assignee[] = [
+  { id: 1, text: 'Samantha Bright', color: '#A7E3A5' },
+  { id: 2, text: 'John Heart', color: '#CFE4FA' },
+  { id: 3, text: 'Todd Hoffman', color: '#F9E2AE' },
+  { id: 4, text: 'Sandra Johnson', color: '#F1BBBC' },
+];
+
+const appointments: Appointment[] = [
+  {
+    id: 1,
+    text: 'Website Re-Design Plan',
+    startDate: new Date(2026, 1, 9, 9, 30),
+    endDate: new Date(2026, 1, 9, 11, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 2,
+    text: 'Install New Router in Dev Room',
+    startDate: new Date(2026, 1, 9, 14, 30),
+    endDate: new Date(2026, 1, 9, 15, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 3,
+    text: 'Approve Personal Computer Upgrade Plan',
+    startDate: new Date(2026, 1, 10, 10, 0),
+    endDate: new Date(2026, 1, 10, 11, 0),
+    assigneeId: [1],
+  },
+  {
+    id: 4,
+    text: 'Final Budget Review',
+    startDate: new Date(2026, 1, 10, 12, 0),
+    endDate: new Date(2026, 1, 10, 13, 35),
+    assigneeId: [1],
+  },
+  {
+    id: 5,
+    text: 'Install New Database',
+    startDate: new Date(2026, 1, 11, 9, 45),
+    endDate: new Date(2026, 1, 11, 11, 15),
+    assigneeId: [4],
+  },
+  {
+    id: 6,
+    text: 'Approve New Online Marketing Strategy',
+    startDate: new Date(2026, 1, 11, 12, 0),
+    endDate: new Date(2026, 1, 11, 14, 0),
+    assigneeId: [2],
+  },
+  {
+    id: 7,
+    text: 'Prepare 2021 Marketing Plan',
+    startDate: new Date(2026, 1, 12, 11, 0),
+    endDate: new Date(2026, 1, 12, 13, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 8,
+    text: 'Brochure Design Review',
+    startDate: new Date(2026, 1, 12, 14, 0),
+    endDate: new Date(2026, 1, 12, 15, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 9,
+    text: 'Create Icons for Website',
+    startDate: new Date(2026, 1, 13, 10, 0),
+    endDate: new Date(2026, 1, 13, 11, 30),
+    assigneeId: [1],
+  },
+  {
+    id: 10,
+    text: 'Launch New Website',
+    startDate: new Date(2026, 1, 13, 12, 20),
+    endDate: new Date(2026, 1, 13, 14, 0),
+    assigneeId: [4],
+  },
+  {
+    id: 11,
+    text: 'Upgrade Server Hardware',
+    startDate: new Date(2026, 1, 13, 14, 30),
+    endDate: new Date(2026, 1, 13, 16, 0),
+    assigneeId: [2],
+  },
+];
+
+@Injectable()
+export class Service {
+  getAppointments(): Appointment[] {
+    return appointments;
+  }
+}
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/index.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/index.html
new file mode 100644
index 000000000000..1ab1fb54a1df
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Angular/index.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
+  <head>
+    <title>DevExtreme Demo</title>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" />
+    <link rel="stylesheet" type="text/css" href="../../../../node_modules/devextreme-dist/css/dx.light.css" />
+
+    <script src="../../../../node_modules/core-js/client/shim.min.js"></script>
+    <script src="../../../../node_modules/zone.js/bundles/zone.umd.js"></script>
+    <script src="../../../../node_modules/reflect-metadata/Reflect.js"></script>
+    <script src="../../../../node_modules/systemjs/dist/system.js"></script>
+
+    <script src="config.js"></script>
+    <script>
+      System.import("app").catch(console.error.bind(console));
+    </script>
+  </head>
+
+  <body class="dx-viewport">
+    <div class="demo-container">
+      <demo-app>Loading...</demo-app>
+    </div>
+  </body>
+</html>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/App.tsx b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/App.tsx
new file mode 100644
index 000000000000..e45defb20c6a
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/App.tsx
@@ -0,0 +1,270 @@
+import React, {
+  useCallback, useMemo, useRef,
+} from 'react';
+import Scheduler, {
+  Form, Editing, Resource, Item,
+} from 'devextreme-react/scheduler';
+import type { SchedulerTypes } from 'devextreme-react/scheduler';
+import SelectBox from 'devextreme-react/select-box';
+import type { SelectBoxTypes } from 'devextreme-react/select-box';
+import type { FormTypes } from 'devextreme-react/form';
+import type { PopupTypes } from 'devextreme-react/popup';
+import type { TagBoxTypes } from 'devextreme-react/tag-box';
+import { custom as customDialog } from 'devextreme/ui/dialog';
+import { data, assignees, type Appointment, type Assignee } from './data.ts';
+
+type dxScheduler = NonNullable<SchedulerTypes.InitializedEvent['component']>;
+type dxForm = NonNullable<FormTypes.InitializedEvent['component']>;
+type dxPopup = NonNullable<PopupTypes.InitializedEvent['component']>;
+
+const currentDate = new Date(2026, 1, 10);
+const views: SchedulerTypes.ViewType[] = ['day', 'week', 'workWeek', 'month'];
+
+const overlappingRuleItems = [
+  { value: 'sameResource', text: 'Allow across resources' },
+  { value: 'allResources', text: 'Disallow all overlaps' },
+];
+
+function getNextDay(date: Date): Date {
+  const next = new Date(date);
+  next.setDate(next.getDate() + 1);
+  return next;
+}
+
+function getEndDate(occurrence: SchedulerTypes.Occurrence): Date {
+  return (occurrence.appointmentData as Appointment).allDay
+    ? getNextDay(occurrence.startDate)
+    : occurrence.endDate;
+}
+
+function isOverlapping(
+  a: SchedulerTypes.Occurrence,
+  b: SchedulerTypes.Occurrence,
+  overlappingRule: string,
+): boolean {
+  const aEnd = getEndDate(a);
+  const bEnd = getEndDate(b);
+  if (a.startDate >= bEnd || b.startDate >= aEnd) return false;
+  if (overlappingRule === 'sameResource') {
+    return (a.appointmentData as Appointment).assigneeId[0] === (b.appointmentData as Appointment).assigneeId[0];
+  }
+  return true;
+}
+
+function detectConflict(
+  scheduler: dxScheduler,
+  newAppointment: Appointment,
+  overlappingRule: string,
+): boolean {
+  const allAppointments = scheduler.getDataSource().items() as Appointment[];
+  const startDate = new Date(newAppointment.startDate);
+  let endDate: Date;
+  if (newAppointment.recurrenceRule) {
+    endDate = scheduler.getEndViewDate();
+  } else if (newAppointment.allDay) {
+    endDate = getNextDay(startDate);
+  } else {
+    endDate = new Date(newAppointment.endDate);
+  }
+
+  const existingOccurrences = scheduler
+    .getOccurrences(startDate, endDate, allAppointments)
+    .filter((occurrence) => (occurrence.appointmentData as Appointment).id !== newAppointment.id);
+
+  const newOccurrences = scheduler.getOccurrences(startDate, endDate, [newAppointment]);
+
+  return newOccurrences.some((newOccurrence) =>
+    existingOccurrences.some((existingOccurrence) =>
+      isOverlapping(newOccurrence, existingOccurrence, overlappingRule),
+    ),
+  );
+}
+
+const assigneeIdEditorOptions = {
+  onValueChanged: (e: TagBoxTypes.ValueChangedEvent) => {
+    if (e.value.length > 1) {
+      e.component.option('value', [e.value[e.value.length - 1]]);
+    }
+  },
+  tagRender: (itemData: Assignee) => tagTemplate(itemData),
+};
+
+const tagTemplate = (itemData: Assignee) => (
+  <div className="dx-tag-content" style={{ backgroundColor: itemData.color, borderColor: itemData.color }}>
+    {itemData.text}
+    <div className="dx-tag-remove-button"></div>
+  </div>
+);
+
+const conflictInformerRender = () => (
+  <div className="conflict-informer">This time slot conflicts with another appointment.</div>
+);
+
+const App = () => {
+  const popupRef = useRef<dxPopup | null>(null);
+  const formRef = useRef<dxForm | null>(null);
+  const showConflictErrorRef = useRef(false);
+  const overlappingRuleRef = useRef('sameResource');
+
+  const setConflictError = useCallback((show: boolean) => {
+    showConflictErrorRef.current = show;
+    formRef.current?.option('elementAttr.class', show ? '' : 'hide-informer');
+  }, []);
+
+  const alertConflictIfNeeded = useCallback((
+    e: SchedulerTypes.AppointmentAddingEvent | SchedulerTypes.AppointmentUpdatingEvent,
+    appointmentData: Appointment,
+  ) => {
+    if (!detectConflict(e.component, appointmentData, overlappingRuleRef.current)) {
+      setConflictError(false);
+      return;
+    }
+
+    e.cancel = true;
+
+    if (popupRef.current?.option('visible')) {
+      setConflictError(true);
+      formRef.current?.validate();
+    } else {
+      const dialog = customDialog({
+        showTitle: false,
+        messageHtml: '<p id="conflict-dialog">This time slot conflicts with another appointment.</p>',
+        buttons: [{
+          type: 'default',
+          text: 'Close',
+          stylingMode: 'contained',
+          onClick: () => {
+            dialog.hide();
+          },
+        }],
+      });
+      dialog.show();
+    }
+  }, [setConflictError]);
+
+  const onAppointmentAdding = useCallback((e: SchedulerTypes.AppointmentAddingEvent) => {
+    alertConflictIfNeeded(e, e.appointmentData as Appointment);
+  }, [alertConflictIfNeeded]);
+
+  const onAppointmentUpdating = useCallback((e: SchedulerTypes.AppointmentUpdatingEvent) => {
+    alertConflictIfNeeded(e, { ...e.oldData, ...e.newData } as Appointment);
+  }, [alertConflictIfNeeded]);
+
+  const popupOptions = useMemo(() => ({
+    onInitialized: (e: PopupTypes.InitializedEvent) => {
+      popupRef.current = e.component ?? null;
+    },
+    onHidden: () => {
+      setConflictError(false);
+      formRef.current?.updateData('assigneeId', []);
+    },
+  }), [setConflictError]);
+
+  const onFormInitialized = useCallback((e: FormTypes.InitializedEvent) => {
+    if (!e.component) return;
+    formRef.current = e.component;
+
+    e.component.on('fieldDataChanged', (fieldEvent: FormTypes.FieldDataChangedEvent) => {
+      if (
+        showConflictErrorRef.current &&
+        ['startDate', 'endDate', 'assigneeId', 'recurrenceRule'].includes(fieldEvent.dataField ?? '')
+      ) {
+        setConflictError(false);
+        formRef.current?.validate();
+      }
+    });
+  }, [setConflictError]);
+
+  const customizeItem = useCallback((item: FormTypes.SimpleItem) => {
+    if (item.name === 'allDayEditor' || item.name === 'recurrenceEndEditor') {
+      item.label = { ...item.label, visible: true };
+    } else if (item.name === 'subjectEditor') {
+      item.editorOptions = item.editorOptions || {};
+      item.editorOptions.placeholder = 'Add title';
+    }
+
+    if (item.name === 'startTimeEditor' || item.name === 'endTimeEditor') {
+      item.validationRules = [
+        { type: 'required' },
+        {
+          type: 'custom',
+          message: 'Time conflict',
+          ignoreEmptyValue: true,
+          reevaluate: true,
+          validationCallback: () => !showConflictErrorRef.current,
+        },
+      ];
+    }
+  }, []);
+
+  return (
+    <>
+      <Scheduler
+        dataSource={data}
+        views={views}
+        defaultCurrentView="week"
+        defaultCurrentDate={currentDate}
+        startDayHour={9}
+        endDayHour={19}
+        height={600}
+        showAllDayPanel={false}
+        allDayPanelMode="hidden"
+        onAppointmentAdding={onAppointmentAdding}
+        onAppointmentUpdating={onAppointmentUpdating}
+      >
+        <Resource
+          fieldExpr="assigneeId"
+          dataSource={assignees}
+          valueExpr="id"
+          colorExpr="color"
+          icon="user"
+          allowMultiple={true}
+        />
+
+        <Editing popup={popupOptions}>
+          <Form
+            labelMode="hidden"
+            onInitialized={onFormInitialized}
+            customizeItem={customizeItem}
+            elementAttr={{ class: 'hide-informer', id: 'form' }}
+          >
+            <Item
+              name="conflictInformer"
+              render={conflictInformerRender}
+            />
+            <Item type="group" name="mainGroup">
+              <Item name="subjectGroup" />
+              <Item name="dateGroup" />
+              <Item name="repeatGroup" />
+              <Item name="assigneeIdGroup">
+                <Item name="assigneeIdIcon" />
+                <Item
+                  name="assigneeId"
+                  isRequired={true}
+                  editorOptions={assigneeIdEditorOptions}
+                />
+              </Item>
+            </Item>
+            <Item type="group" name="recurrenceGroup" />
+          </Form>
+        </Editing>
+      </Scheduler>
+
+      <div className="options">
+        <div className="option">
+          <span>Overlapping Rule</span>
+          <SelectBox
+            items={overlappingRuleItems}
+            valueExpr="value"
+            displayExpr="text"
+            defaultValue="sameResource"
+            width={200}
+            onValueChanged={(e: SelectBoxTypes.ValueChangedEvent) => { overlappingRuleRef.current = e.value; }}
+          />
+        </div>
+      </div>
+    </>
+  );
+};
+
+export default App;
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/data.ts b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/data.ts
new file mode 100644
index 000000000000..a1f288141c5d
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/data.ts
@@ -0,0 +1,102 @@
+export interface Appointment {
+  id: number;
+  text: string;
+  startDate: Date;
+  endDate: Date;
+  assigneeId: number[];
+  recurrenceRule?: string;
+  allDay?: boolean;
+}
+
+export interface Assignee {
+  id: number;
+  text: string;
+  color: string;
+}
+
+export const assignees: Assignee[] = [
+  { id: 1, text: 'Samantha Bright', color: '#A7E3A5' },
+  { id: 2, text: 'John Heart', color: '#CFE4FA' },
+  { id: 3, text: 'Todd Hoffman', color: '#F9E2AE' },
+  { id: 4, text: 'Sandra Johnson', color: '#F1BBBC' },
+];
+
+export const data: Appointment[] = [
+  {
+    id: 1,
+    text: 'Website Re-Design Plan',
+    startDate: new Date(2026, 1, 9, 9, 30),
+    endDate: new Date(2026, 1, 9, 11, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 2,
+    text: 'Install New Router in Dev Room',
+    startDate: new Date(2026, 1, 9, 14, 30),
+    endDate: new Date(2026, 1, 9, 15, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 3,
+    text: 'Approve Personal Computer Upgrade Plan',
+    startDate: new Date(2026, 1, 10, 10, 0),
+    endDate: new Date(2026, 1, 10, 11, 0),
+    assigneeId: [1],
+  },
+  {
+    id: 4,
+    text: 'Final Budget Review',
+    startDate: new Date(2026, 1, 10, 12, 0),
+    endDate: new Date(2026, 1, 10, 13, 35),
+    assigneeId: [1],
+  },
+  {
+    id: 5,
+    text: 'Install New Database',
+    startDate: new Date(2026, 1, 11, 9, 45),
+    endDate: new Date(2026, 1, 11, 11, 15),
+    assigneeId: [4],
+  },
+  {
+    id: 6,
+    text: 'Approve New Online Marketing Strategy',
+    startDate: new Date(2026, 1, 11, 12, 0),
+    endDate: new Date(2026, 1, 11, 14, 0),
+    assigneeId: [2],
+  },
+  {
+    id: 7,
+    text: 'Prepare 2021 Marketing Plan',
+    startDate: new Date(2026, 1, 12, 11, 0),
+    endDate: new Date(2026, 1, 12, 13, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 8,
+    text: 'Brochure Design Review',
+    startDate: new Date(2026, 1, 12, 14, 0),
+    endDate: new Date(2026, 1, 12, 15, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 9,
+    text: 'Create Icons for Website',
+    startDate: new Date(2026, 1, 13, 10, 0),
+    endDate: new Date(2026, 1, 13, 11, 30),
+    assigneeId: [1],
+  },
+  {
+    id: 10,
+    text: 'Launch New Website',
+    startDate: new Date(2026, 1, 13, 12, 20),
+    endDate: new Date(2026, 1, 13, 14, 0),
+    assigneeId: [4],
+  },
+  {
+    id: 11,
+    text: 'Upgrade Server Hardware',
+    startDate: new Date(2026, 1, 13, 14, 30),
+    endDate: new Date(2026, 1, 13, 16, 0),
+    assigneeId: [2],
+  },
+];
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.html
new file mode 100644
index 000000000000..ee451f8288ff
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <title>DevExtreme Demo</title>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" />
+    <link rel="stylesheet" type="text/css" href="../../../../node_modules/devextreme-dist/css/dx.light.css" />
+    <link rel="stylesheet" type="text/css" href="styles.css" />
+
+    <script src="../../../../node_modules/core-js/client/shim.min.js"></script>
+    <script src="../../../../node_modules/systemjs/dist/system.js"></script>
+    <script type="text/javascript" src="config.js"></script>
+    <script type="text/javascript">
+      System.import("./index.tsx");
+    </script>
+  </head>
+
+  <body class="dx-viewport">
+    <div class="demo-container">
+      <div id="app"></div>
+    </div>
+  </body>
+</html>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.tsx b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.tsx
new file mode 100644
index 000000000000..8acbec4b6179
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/index.tsx
@@ -0,0 +1,9 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+
+import App from './App.tsx';
+
+ReactDOM.render(
+  <App />,
+  document.getElementById('app'),
+);
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/styles.css b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/styles.css
new file mode 100644
index 000000000000..4dcecbdb8a0b
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/React/styles.css
@@ -0,0 +1,66 @@
+.dx-scheduler-appointment {
+  color: #242424;
+}
+
+.options {
+  padding: 20px;
+  background-color: rgba(191, 191, 191, 0.15);
+  margin-top: 20px;
+}
+
+.option {
+  margin-top: 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.hide-informer .dx-item:has(.conflict-informer) {
+  display: none !important;
+}
+
+.conflict-informer {
+  background-color: #FCEAE8;
+  color: #C50F1F;
+  font-size: 12px;
+  padding: 0 12px;
+  height: 36px;
+  line-height: 36px;
+  box-sizing: border-box;
+  margin-bottom: 8px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-overlay-content {
+  width: 280px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-content {
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-buttons {
+  padding-top: 0;
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-toolbar-center,
+.dx-dialog:has(#conflict-dialog) .dx-button {
+  width: 100%;
+}
+
+.dx-scheduler-form-main-group .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-field-item-content,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child .dx-field-item-content {
+  overflow: visible;
+}
+
+#form .dx-scheduler-form-main-group,
+#form .dx-scheduler-form-recurrence-group {
+  padding-top: 0;
+}
+
+#form:not(.hide-informer) .dx-scheduler-form-recurrence-group.dx-scheduler-form-recurrence-group-hidden,
+#form:not(.hide-informer) .dx-scheduler-form-main-group.dx-scheduler-form-main-group-hidden {
+  top: 44px;
+}
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/App.js b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/App.js
new file mode 100644
index 000000000000..b85c079efcba
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/App.js
@@ -0,0 +1,251 @@
+import React, { useCallback, useMemo, useRef } from 'react';
+import Scheduler, {
+  Form, Editing, Resource, Item,
+} from 'devextreme-react/scheduler';
+import SelectBox from 'devextreme-react/select-box';
+import { custom as customDialog } from 'devextreme/ui/dialog';
+import { data, assignees } from './data.js';
+
+const currentDate = new Date(2026, 1, 10);
+const views = ['day', 'week', 'workWeek', 'month'];
+const overlappingRuleItems = [
+  { value: 'sameResource', text: 'Allow across resources' },
+  { value: 'allResources', text: 'Disallow all overlaps' },
+];
+function getNextDay(date) {
+  const next = new Date(date);
+  next.setDate(next.getDate() + 1);
+  return next;
+}
+function getEndDate(occurrence) {
+  return occurrence.appointmentData.allDay ? getNextDay(occurrence.startDate) : occurrence.endDate;
+}
+function isOverlapping(a, b, overlappingRule) {
+  const aEnd = getEndDate(a);
+  const bEnd = getEndDate(b);
+  if (a.startDate >= bEnd || b.startDate >= aEnd) return false;
+  if (overlappingRule === 'sameResource') {
+    return a.appointmentData.assigneeId[0] === b.appointmentData.assigneeId[0];
+  }
+  return true;
+}
+function detectConflict(scheduler, newAppointment, overlappingRule) {
+  const allAppointments = scheduler.getDataSource().items();
+  const startDate = new Date(newAppointment.startDate);
+  let endDate;
+  if (newAppointment.recurrenceRule) {
+    endDate = scheduler.getEndViewDate();
+  } else if (newAppointment.allDay) {
+    endDate = getNextDay(startDate);
+  } else {
+    endDate = new Date(newAppointment.endDate);
+  }
+  const existingOccurrences = scheduler
+    .getOccurrences(startDate, endDate, allAppointments)
+    .filter((occurrence) => occurrence.appointmentData.id !== newAppointment.id);
+  const newOccurrences = scheduler.getOccurrences(startDate, endDate, [newAppointment]);
+  return newOccurrences.some((newOccurrence) =>
+    existingOccurrences.some((existingOccurrence) =>
+      isOverlapping(newOccurrence, existingOccurrence, overlappingRule),
+    ),
+  );
+}
+const assigneeIdEditorOptions = {
+  onValueChanged: (e) => {
+    if (e.value.length > 1) {
+      e.component.option('value', [e.value[e.value.length - 1]]);
+    }
+  },
+  tagRender: (itemData) => tagTemplate(itemData),
+};
+const tagTemplate = (itemData) => (
+  <div
+    className="dx-tag-content"
+    style={{ backgroundColor: itemData.color, borderColor: itemData.color }}
+  >
+    {itemData.text}
+    <div className="dx-tag-remove-button"></div>
+  </div>
+);
+const conflictInformerRender = () => (
+  <div className="conflict-informer">This time slot conflicts with another appointment.</div>
+);
+const App = () => {
+  const popupRef = useRef(null);
+  const formRef = useRef(null);
+  const showConflictErrorRef = useRef(false);
+  const overlappingRuleRef = useRef('sameResource');
+  const setConflictError = useCallback((show) => {
+    showConflictErrorRef.current = show;
+    formRef.current?.option('elementAttr.class', show ? '' : 'hide-informer');
+  }, []);
+  const alertConflictIfNeeded = useCallback(
+    (e, appointmentData) => {
+      if (!detectConflict(e.component, appointmentData, overlappingRuleRef.current)) {
+        setConflictError(false);
+        return;
+      }
+      e.cancel = true;
+      if (popupRef.current?.option('visible')) {
+        setConflictError(true);
+        formRef.current?.validate();
+      } else {
+        const dialog = customDialog({
+          showTitle: false,
+          messageHtml: '<p id="conflict-dialog">This time slot conflicts with another appointment.</p>',
+          buttons: [
+            {
+              type: 'default',
+              text: 'Close',
+              stylingMode: 'contained',
+              onClick: () => {
+                dialog.hide();
+              },
+            },
+          ],
+        });
+        dialog.show();
+      }
+    },
+    [setConflictError],
+  );
+  const onAppointmentAdding = useCallback(
+    (e) => {
+      alertConflictIfNeeded(e, e.appointmentData);
+    },
+    [alertConflictIfNeeded],
+  );
+  const onAppointmentUpdating = useCallback(
+    (e) => {
+      alertConflictIfNeeded(e, { ...e.oldData, ...e.newData });
+    },
+    [alertConflictIfNeeded],
+  );
+  const popupOptions = useMemo(
+    () => ({
+      onInitialized: (e) => {
+        popupRef.current = e.component ?? null;
+      },
+      onHidden: () => {
+        setConflictError(false);
+        formRef.current?.updateData('assigneeId', []);
+      },
+    }),
+    [setConflictError],
+  );
+  const onFormInitialized = useCallback(
+    (e) => {
+      if (!e.component) return;
+      formRef.current = e.component;
+      e.component.on('fieldDataChanged', (fieldEvent) => {
+        if (
+          showConflictErrorRef.current &&
+          ['startDate', 'endDate', 'assigneeId', 'recurrenceRule'].includes(
+            fieldEvent.dataField ?? '',
+          )
+        ) {
+          setConflictError(false);
+          formRef.current?.validate();
+        }
+      });
+    },
+    [setConflictError],
+  );
+  const customizeItem = useCallback((item) => {
+    if (item.name === 'allDayEditor' || item.name === 'recurrenceEndEditor') {
+      item.label = { ...item.label, visible: true };
+    } else if (item.name === 'subjectEditor') {
+      item.editorOptions = item.editorOptions || {};
+      item.editorOptions.placeholder = 'Add title';
+    }
+    if (item.name === 'startTimeEditor' || item.name === 'endTimeEditor') {
+      item.validationRules = [
+        { type: 'required' },
+        {
+          type: 'custom',
+          message: 'Time conflict',
+          ignoreEmptyValue: true,
+          reevaluate: true,
+          validationCallback: () => !showConflictErrorRef.current,
+        },
+      ];
+    }
+  }, []);
+  return (
+    <>
+      <Scheduler
+        dataSource={data}
+        views={views}
+        defaultCurrentView="week"
+        defaultCurrentDate={currentDate}
+        startDayHour={9}
+        endDayHour={19}
+        height={600}
+        showAllDayPanel={false}
+        allDayPanelMode="hidden"
+        onAppointmentAdding={onAppointmentAdding}
+        onAppointmentUpdating={onAppointmentUpdating}
+      >
+        <Resource
+          fieldExpr="assigneeId"
+          dataSource={assignees}
+          valueExpr="id"
+          colorExpr="color"
+          icon="user"
+          allowMultiple={true}
+        />
+
+        <Editing popup={popupOptions}>
+          <Form
+            labelMode="hidden"
+            onInitialized={onFormInitialized}
+            customizeItem={customizeItem}
+            elementAttr={{ class: 'hide-informer', id: 'form' }}
+          >
+            <Item
+              name="conflictInformer"
+              render={conflictInformerRender}
+            />
+            <Item
+              type="group"
+              name="mainGroup"
+            >
+              <Item name="subjectGroup" />
+              <Item name="dateGroup" />
+              <Item name="repeatGroup" />
+              <Item name="assigneeIdGroup">
+                <Item name="assigneeIdIcon" />
+                <Item
+                  name="assigneeId"
+                  isRequired={true}
+                  editorOptions={assigneeIdEditorOptions}
+                />
+              </Item>
+            </Item>
+            <Item
+              type="group"
+              name="recurrenceGroup"
+            />
+          </Form>
+        </Editing>
+      </Scheduler>
+
+      <div className="options">
+        <div className="option">
+          <span>Overlapping Rule</span>
+          <SelectBox
+            items={overlappingRuleItems}
+            valueExpr="value"
+            displayExpr="text"
+            defaultValue="sameResource"
+            width={200}
+            onValueChanged={(e) => {
+              overlappingRuleRef.current = e.value;
+            }}
+          />
+        </div>
+      </div>
+    </>
+  );
+};
+export default App;
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/data.js b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/data.js
new file mode 100644
index 000000000000..2e1e037aedfe
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/data.js
@@ -0,0 +1,85 @@
+export const assignees = [
+  { id: 1, text: 'Samantha Bright', color: '#A7E3A5' },
+  { id: 2, text: 'John Heart', color: '#CFE4FA' },
+  { id: 3, text: 'Todd Hoffman', color: '#F9E2AE' },
+  { id: 4, text: 'Sandra Johnson', color: '#F1BBBC' },
+];
+export const data = [
+  {
+    id: 1,
+    text: 'Website Re-Design Plan',
+    startDate: new Date(2026, 1, 9, 9, 30),
+    endDate: new Date(2026, 1, 9, 11, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 2,
+    text: 'Install New Router in Dev Room',
+    startDate: new Date(2026, 1, 9, 14, 30),
+    endDate: new Date(2026, 1, 9, 15, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 3,
+    text: 'Approve Personal Computer Upgrade Plan',
+    startDate: new Date(2026, 1, 10, 10, 0),
+    endDate: new Date(2026, 1, 10, 11, 0),
+    assigneeId: [1],
+  },
+  {
+    id: 4,
+    text: 'Final Budget Review',
+    startDate: new Date(2026, 1, 10, 12, 0),
+    endDate: new Date(2026, 1, 10, 13, 35),
+    assigneeId: [1],
+  },
+  {
+    id: 5,
+    text: 'Install New Database',
+    startDate: new Date(2026, 1, 11, 9, 45),
+    endDate: new Date(2026, 1, 11, 11, 15),
+    assigneeId: [4],
+  },
+  {
+    id: 6,
+    text: 'Approve New Online Marketing Strategy',
+    startDate: new Date(2026, 1, 11, 12, 0),
+    endDate: new Date(2026, 1, 11, 14, 0),
+    assigneeId: [2],
+  },
+  {
+    id: 7,
+    text: 'Prepare 2021 Marketing Plan',
+    startDate: new Date(2026, 1, 12, 11, 0),
+    endDate: new Date(2026, 1, 12, 13, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 8,
+    text: 'Brochure Design Review',
+    startDate: new Date(2026, 1, 12, 14, 0),
+    endDate: new Date(2026, 1, 12, 15, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 9,
+    text: 'Create Icons for Website',
+    startDate: new Date(2026, 1, 13, 10, 0),
+    endDate: new Date(2026, 1, 13, 11, 30),
+    assigneeId: [1],
+  },
+  {
+    id: 10,
+    text: 'Launch New Website',
+    startDate: new Date(2026, 1, 13, 12, 20),
+    endDate: new Date(2026, 1, 13, 14, 0),
+    assigneeId: [4],
+  },
+  {
+    id: 11,
+    text: 'Upgrade Server Hardware',
+    startDate: new Date(2026, 1, 13, 14, 30),
+    endDate: new Date(2026, 1, 13, 16, 0),
+    assigneeId: [2],
+  },
+];
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.html
new file mode 100644
index 000000000000..db31b0fd60c6
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <title>DevExtreme Demo</title>
+    <meta
+      http-equiv="X-UA-Compatible"
+      content="IE=edge"
+    />
+    <meta
+      http-equiv="Content-Type"
+      content="text/html; charset=utf-8"
+    />
+    <meta
+      name="viewport"
+      content="width=device-width, initial-scale=1.0, maximum-scale=5.0"
+    />
+    <link
+      rel="stylesheet"
+      type="text/css"
+      href="../../../../node_modules/devextreme-dist/css/dx.light.css"
+    />
+    <link
+      rel="stylesheet"
+      type="text/css"
+      href="styles.css"
+    />
+
+    <script src="../../../../node_modules/core-js/client/shim.min.js"></script>
+    <script src="../../../../node_modules/systemjs/dist/system.js"></script>
+    <script
+      type="text/javascript"
+      src="config.js"
+    ></script>
+    <script type="text/javascript">
+      System.import("./index.js");
+    </script>
+  </head>
+
+  <body class="dx-viewport">
+    <div class="demo-container">
+      <div id="app"></div>
+    </div>
+  </body>
+</html>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.js b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.js
new file mode 100644
index 000000000000..b853e0be8242
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/index.js
@@ -0,0 +1,5 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import App from './App.js';
+
+ReactDOM.render(<App />, document.getElementById('app'));
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/styles.css b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/styles.css
new file mode 100644
index 000000000000..4dcecbdb8a0b
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/ReactJs/styles.css
@@ -0,0 +1,66 @@
+.dx-scheduler-appointment {
+  color: #242424;
+}
+
+.options {
+  padding: 20px;
+  background-color: rgba(191, 191, 191, 0.15);
+  margin-top: 20px;
+}
+
+.option {
+  margin-top: 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.hide-informer .dx-item:has(.conflict-informer) {
+  display: none !important;
+}
+
+.conflict-informer {
+  background-color: #FCEAE8;
+  color: #C50F1F;
+  font-size: 12px;
+  padding: 0 12px;
+  height: 36px;
+  line-height: 36px;
+  box-sizing: border-box;
+  margin-bottom: 8px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-overlay-content {
+  width: 280px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-content {
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-buttons {
+  padding-top: 0;
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-toolbar-center,
+.dx-dialog:has(#conflict-dialog) .dx-button {
+  width: 100%;
+}
+
+.dx-scheduler-form-main-group .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-field-item-content,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child .dx-field-item-content {
+  overflow: visible;
+}
+
+#form .dx-scheduler-form-main-group,
+#form .dx-scheduler-form-recurrence-group {
+  padding-top: 0;
+}
+
+#form:not(.hide-informer) .dx-scheduler-form-recurrence-group.dx-scheduler-form-recurrence-group-hidden,
+#form:not(.hide-informer) .dx-scheduler-form-main-group.dx-scheduler-form-main-group-hidden {
+  top: 44px;
+}
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/App.vue b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/App.vue
new file mode 100644
index 000000000000..a7e6001aebd1
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/App.vue
@@ -0,0 +1,342 @@
+<template>
+  <DxScheduler
+    :data-source="data"
+    :views="views"
+    :current-view="'week'"
+    :current-date="currentDate"
+    :start-day-hour="9"
+    :end-day-hour="19"
+    :height="600"
+    :show-all-day-panel="false"
+    all-day-panel-mode="hidden"
+    @appointment-adding="onAppointmentAdding"
+    @appointment-updating="onAppointmentUpdating"
+  >
+    <DxResource
+      field-expr="assigneeId"
+      :data-source="assignees"
+      value-expr="id"
+      color-expr="color"
+      icon="user"
+      :allow-multiple="true"
+    />
+
+    <DxEditing :popup="popupOptions">
+      <DxForm
+        label-mode="hidden"
+        :customize-item="customizeItem"
+        :element-attr="formElementAttr"
+        @initialized="onFormInitialized"
+      >
+        <DxItem
+          name="conflictInformer"
+          template="conflict-informer-template"
+        />
+        <DxItem
+          type="group"
+          name="mainGroup"
+        >
+          <DxItem name="subjectGroup"/>
+          <DxItem name="dateGroup"/>
+          <DxItem name="repeatGroup"/>
+          <DxItem name="assigneeIdGroup">
+            <DxItem name="assigneeIdIcon"/>
+            <DxItem
+              name="assigneeId"
+              :is-required="true"
+              :editor-options="assigneeIdEditorOptions"
+            />
+          </DxItem>
+        </DxItem>
+        <DxItem
+          type="group"
+          name="recurrenceGroup"
+        />
+      </DxForm>
+    </DxEditing>
+
+    <template #conflict-informer-template>
+      <div class="conflict-informer">This time slot conflicts with another appointment.</div>
+    </template>
+
+    <template #tagTemplate="{ data: itemData }">
+      <div
+        class="dx-tag-content"
+        :style="{ backgroundColor: itemData.color, borderColor: itemData.color }"
+      >
+        {{ itemData.text }}
+        <div class="dx-tag-remove-button"/>
+      </div>
+    </template>
+  </DxScheduler>
+
+  <div class="options">
+    <div class="option">
+      <span>Overlapping Rule</span>
+      <DxSelectBox
+        :items="overlappingRuleItems"
+        value-expr="value"
+        display-expr="text"
+        value="sameResource"
+        :width="200"
+        @value-changed="onOverlappingRuleChanged"
+      />
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import DxScheduler, {
+  DxResource,
+  DxEditing,
+  DxForm,
+  DxItem,
+  type DxSchedulerTypes,
+} from 'devextreme-vue/scheduler';
+import DxSelectBox, { type DxSelectBoxTypes } from 'devextreme-vue/select-box';
+import { custom as customDialog } from 'devextreme/ui/dialog';
+import type { DxFormTypes } from 'devextreme-vue/form';
+import type { DxTagBoxTypes } from 'devextreme-vue/tag-box';
+import type { DxPopupTypes } from 'devextreme-vue/popup';
+import { data, assignees, type Appointment } from './data.ts';
+
+type dxScheduler = NonNullable<DxSchedulerTypes.InitializedEvent['component']>;
+type dxForm = NonNullable<DxFormTypes.InitializedEvent['component']>;
+type dxPopup = NonNullable<DxPopupTypes.InitializedEvent['component']>;
+
+let form: dxForm | undefined;
+let popup: dxPopup | undefined;
+let showConflictError = false;
+let overlappingRule = 'sameResource';
+
+const currentDate = new Date(2026, 1, 10);
+const views: DxSchedulerTypes.ViewType[] = ['day', 'week', 'workWeek', 'month'];
+
+const formElementAttr = { class: 'hide-informer', id: 'form' };
+
+const overlappingRuleItems = [
+  { value: 'sameResource', text: 'Allow across resources' },
+  { value: 'allResources', text: 'Disallow all overlaps' },
+];
+
+function getNextDay(date: Date): Date {
+  const next = new Date(date);
+  next.setDate(next.getDate() + 1);
+  return next;
+}
+
+function getEndDate(occurrence: DxSchedulerTypes.Occurrence): Date {
+  return (occurrence.appointmentData as Appointment).allDay
+    ? getNextDay(occurrence.startDate)
+    : occurrence.endDate;
+}
+
+function isOverlapping(a: DxSchedulerTypes.Occurrence, b: DxSchedulerTypes.Occurrence): boolean {
+  const aEnd = getEndDate(a);
+  const bEnd = getEndDate(b);
+  if (a.startDate >= bEnd || b.startDate >= aEnd) return false;
+  if (overlappingRule === 'sameResource') {
+    return (a.appointmentData as Appointment).assigneeId[0] ===
+    (b.appointmentData as Appointment).assigneeId[0];
+  }
+  return true;
+}
+
+function detectConflict(scheduler: dxScheduler, newAppointment: Appointment): boolean {
+  const allAppointments = scheduler.getDataSource().items() as Appointment[];
+  const startDate = new Date(newAppointment.startDate);
+  let endDate: Date;
+  if (newAppointment.recurrenceRule) {
+    endDate = scheduler.getEndViewDate();
+  } else if (newAppointment.allDay) {
+    endDate = getNextDay(startDate);
+  } else {
+    endDate = new Date(newAppointment.endDate);
+  }
+
+  const existingOccurrences = scheduler
+    .getOccurrences(startDate, endDate, allAppointments)
+    .filter((occurrence) => (occurrence.appointmentData as Appointment).id !== newAppointment.id);
+
+  const newOccurrences = scheduler.getOccurrences(startDate, endDate, [newAppointment]);
+
+  return newOccurrences.some((newOccurrence) =>
+    existingOccurrences.some((existingOccurrence) =>
+      isOverlapping(newOccurrence, existingOccurrence),
+    ),
+  );
+}
+
+const assigneeIdEditorOptions = {
+  onValueChanged: (e: DxTagBoxTypes.ValueChangedEvent) => {
+    if (e.value.length > 1) {
+      e.component.option('value', [e.value[e.value.length - 1]]);
+    }
+  },
+  tagTemplate: 'tagTemplate',
+};
+
+function setConflictError(show: boolean) {
+  showConflictError = show;
+  form?.option('elementAttr.class', show ? '' : 'hide-informer');
+}
+
+const popupOptions = {
+  onInitialized: (e: DxPopupTypes.InitializedEvent) => {
+    popup = e.component as dxPopup;
+  },
+  onHidden: () => {
+    setConflictError(false);
+    form?.updateData('assigneeId', []);
+  },
+};
+
+const alertConflictIfNeeded = (
+  e: DxSchedulerTypes.AppointmentAddingEvent | DxSchedulerTypes.AppointmentUpdatingEvent,
+  appointmentData: Appointment,
+) => {
+  if (!detectConflict(e.component, appointmentData)) {
+    setConflictError(false);
+    return;
+  }
+
+  e.cancel = true;
+
+  if (popup?.option('visible')) {
+    setConflictError(true);
+    form?.validate();
+  } else {
+    const dialog = customDialog({
+      showTitle: false,
+      messageHtml: '<p id="conflict-dialog">This time slot conflicts with another appointment.</p>',
+      buttons: [{
+        type: 'default',
+        text: 'Close',
+        stylingMode: 'contained',
+        onClick: () => {
+          dialog.hide();
+        },
+      }],
+    });
+    dialog.show();
+  }
+};
+
+const onAppointmentAdding = (e: DxSchedulerTypes.AppointmentAddingEvent) => {
+  alertConflictIfNeeded(e, e.appointmentData as Appointment);
+};
+
+const onAppointmentUpdating = (e: DxSchedulerTypes.AppointmentUpdatingEvent) => {
+  alertConflictIfNeeded(e, { ...e.oldData, ...e.newData } as Appointment);
+};
+
+const onFormInitialized = (e: DxFormTypes.InitializedEvent) => {
+  form = e.component;
+
+  e.component!.on('fieldDataChanged', (fieldEvent: { dataField: string }) => {
+    if (
+      showConflictError &&
+      ['startDate', 'endDate', 'assigneeId', 'recurrenceRule'].includes(fieldEvent.dataField)
+    ) {
+      setConflictError(false);
+      form?.validate();
+    }
+  });
+};
+
+const customizeItem = (item: DxFormTypes.SimpleItem) => {
+  if (item.name === 'allDayEditor' || item.name === 'recurrenceEndEditor') {
+    item.label!.visible = true;
+  } else if (item.name === 'subjectEditor') {
+    item.editorOptions = item.editorOptions || {};
+    item.editorOptions.placeholder = 'Add title';
+  }
+
+  if (item.name === 'startTimeEditor' || item.name === 'endTimeEditor') {
+    item.validationRules = [
+      { type: 'required' },
+      {
+        type: 'custom',
+        message: 'Time conflict',
+        ignoreEmptyValue: true,
+        reevaluate: true,
+        validationCallback: () => !showConflictError,
+      },
+    ];
+  }
+};
+
+const onOverlappingRuleChanged = (e: DxSelectBoxTypes.ValueChangedEvent) => {
+  overlappingRule = e.value;
+};
+</script>
+
+<style>
+.dx-scheduler-appointment {
+  color: #242424;
+}
+
+.options {
+  padding: 20px;
+  background-color: rgba(191, 191, 191, 0.15);
+  margin-top: 20px;
+}
+
+.option {
+  margin-top: 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.hide-informer .dx-item:has(.conflict-informer) {
+  display: none !important;
+}
+
+.conflict-informer {
+  background-color: #FCEAE8;
+  color: #C50F1F;
+  font-size: 12px;
+  padding: 0 12px;
+  height: 36px;
+  line-height: 36px;
+  box-sizing: border-box;
+  margin-bottom: 8px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-overlay-content {
+  width: 280px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-content {
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-buttons {
+  padding-top: 0;
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-toolbar-center,
+.dx-dialog:has(#conflict-dialog) .dx-button {
+  width: 100%;
+}
+
+.dx-scheduler-form-main-group .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-field-item-content,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-item:last-child .dx-field-item-content {
+  overflow: visible;
+}
+
+#form .dx-scheduler-form-main-group,
+#form .dx-scheduler-form-recurrence-group {
+  padding-top: 0;
+}
+
+#form:not(.hide-informer) .dx-scheduler-form-recurrence-group.dx-scheduler-form-recurrence-group-hidden,
+#form:not(.hide-informer) .dx-scheduler-form-main-group.dx-scheduler-form-main-group-hidden {
+  top: 44px;
+}
+
+</style>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/data.ts b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/data.ts
new file mode 100644
index 000000000000..a1f288141c5d
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/data.ts
@@ -0,0 +1,102 @@
+export interface Appointment {
+  id: number;
+  text: string;
+  startDate: Date;
+  endDate: Date;
+  assigneeId: number[];
+  recurrenceRule?: string;
+  allDay?: boolean;
+}
+
+export interface Assignee {
+  id: number;
+  text: string;
+  color: string;
+}
+
+export const assignees: Assignee[] = [
+  { id: 1, text: 'Samantha Bright', color: '#A7E3A5' },
+  { id: 2, text: 'John Heart', color: '#CFE4FA' },
+  { id: 3, text: 'Todd Hoffman', color: '#F9E2AE' },
+  { id: 4, text: 'Sandra Johnson', color: '#F1BBBC' },
+];
+
+export const data: Appointment[] = [
+  {
+    id: 1,
+    text: 'Website Re-Design Plan',
+    startDate: new Date(2026, 1, 9, 9, 30),
+    endDate: new Date(2026, 1, 9, 11, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 2,
+    text: 'Install New Router in Dev Room',
+    startDate: new Date(2026, 1, 9, 14, 30),
+    endDate: new Date(2026, 1, 9, 15, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 3,
+    text: 'Approve Personal Computer Upgrade Plan',
+    startDate: new Date(2026, 1, 10, 10, 0),
+    endDate: new Date(2026, 1, 10, 11, 0),
+    assigneeId: [1],
+  },
+  {
+    id: 4,
+    text: 'Final Budget Review',
+    startDate: new Date(2026, 1, 10, 12, 0),
+    endDate: new Date(2026, 1, 10, 13, 35),
+    assigneeId: [1],
+  },
+  {
+    id: 5,
+    text: 'Install New Database',
+    startDate: new Date(2026, 1, 11, 9, 45),
+    endDate: new Date(2026, 1, 11, 11, 15),
+    assigneeId: [4],
+  },
+  {
+    id: 6,
+    text: 'Approve New Online Marketing Strategy',
+    startDate: new Date(2026, 1, 11, 12, 0),
+    endDate: new Date(2026, 1, 11, 14, 0),
+    assigneeId: [2],
+  },
+  {
+    id: 7,
+    text: 'Prepare 2021 Marketing Plan',
+    startDate: new Date(2026, 1, 12, 11, 0),
+    endDate: new Date(2026, 1, 12, 13, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 8,
+    text: 'Brochure Design Review',
+    startDate: new Date(2026, 1, 12, 14, 0),
+    endDate: new Date(2026, 1, 12, 15, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 9,
+    text: 'Create Icons for Website',
+    startDate: new Date(2026, 1, 13, 10, 0),
+    endDate: new Date(2026, 1, 13, 11, 30),
+    assigneeId: [1],
+  },
+  {
+    id: 10,
+    text: 'Launch New Website',
+    startDate: new Date(2026, 1, 13, 12, 20),
+    endDate: new Date(2026, 1, 13, 14, 0),
+    assigneeId: [4],
+  },
+  {
+    id: 11,
+    text: 'Upgrade Server Hardware',
+    startDate: new Date(2026, 1, 13, 14, 30),
+    endDate: new Date(2026, 1, 13, 16, 0),
+    assigneeId: [2],
+  },
+];
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.html
new file mode 100644
index 000000000000..c3ac7d2ffbef
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <title>DevExtreme Demo</title>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" />
+    <link rel="stylesheet" type="text/css" href="../../../../node_modules/devextreme-dist/css/dx.light.css" />
+
+    <script src="../../../../node_modules/typescript/lib/typescript.js"></script>
+    <script type="module">
+      import * as vueCompilerSFC from "../../../../node_modules/@vue/compiler-sfc/dist/compiler-sfc.esm-browser.js";
+
+      window.vueCompilerSFC = vueCompilerSFC;
+    </script>
+    <script src="../../../../node_modules/core-js/client/shim.min.js"></script>
+    <script src="../../../../node_modules/systemjs/dist/system.js"></script>
+    <script type="text/javascript" src="config.js"></script>
+    <script type="text/javascript">
+      System.import("./index.ts");
+    </script>
+  </head>
+
+  <body class="dx-viewport">
+    <div class="demo-container">
+      <div id="app"> </div>
+    </div>
+  </body>
+</html>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.ts b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.ts
new file mode 100644
index 000000000000..684d04215d72
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/Vue/index.ts
@@ -0,0 +1,4 @@
+import { createApp } from 'vue';
+import App from './App.vue';
+
+createApp(App).mount('#app');
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/data.js b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/data.js
new file mode 100644
index 000000000000..65546ac13a93
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/data.js
@@ -0,0 +1,86 @@
+const assignees = [
+  { id: 1, text: 'Samantha Bright', color: '#A7E3A5' },
+  { id: 2, text: 'John Heart', color: '#CFE4FA' },
+  { id: 3, text: 'Todd Hoffman', color: '#F9E2AE' },
+  { id: 4, text: 'Sandra Johnson', color: '#F1BBBC' },
+];
+
+const data = [
+  {
+    id: 1,
+    text: 'Website Re-Design Plan',
+    startDate: new Date(2026, 1, 9, 9, 30),
+    endDate: new Date(2026, 1, 9, 11, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 2,
+    text: 'Install New Router in Dev Room',
+    startDate: new Date(2026, 1, 9, 14, 30),
+    endDate: new Date(2026, 1, 9, 15, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 3,
+    text: 'Approve Personal Computer Upgrade Plan',
+    startDate: new Date(2026, 1, 10, 10, 0),
+    endDate: new Date(2026, 1, 10, 11, 0),
+    assigneeId: [1],
+  },
+  {
+    id: 4,
+    text: 'Final Budget Review',
+    startDate: new Date(2026, 1, 10, 12, 0),
+    endDate: new Date(2026, 1, 10, 13, 35),
+    assigneeId: [1],
+  },
+  {
+    id: 5,
+    text: 'Install New Database',
+    startDate: new Date(2026, 1, 11, 9, 45),
+    endDate: new Date(2026, 1, 11, 11, 15),
+    assigneeId: [4],
+  },
+  {
+    id: 6,
+    text: 'Approve New Online Marketing Strategy',
+    startDate: new Date(2026, 1, 11, 12, 0),
+    endDate: new Date(2026, 1, 11, 14, 0),
+    assigneeId: [2],
+  },
+  {
+    id: 7,
+    text: 'Prepare 2021 Marketing Plan',
+    startDate: new Date(2026, 1, 12, 11, 0),
+    endDate: new Date(2026, 1, 12, 13, 30),
+    assigneeId: [3],
+  },
+  {
+    id: 8,
+    text: 'Brochure Design Review',
+    startDate: new Date(2026, 1, 12, 14, 0),
+    endDate: new Date(2026, 1, 12, 15, 30),
+    assigneeId: [2],
+  },
+  {
+    id: 9,
+    text: 'Create Icons for Website',
+    startDate: new Date(2026, 1, 13, 10, 0),
+    endDate: new Date(2026, 1, 13, 11, 30),
+    assigneeId: [1],
+  },
+  {
+    id: 10,
+    text: 'Launch New Website',
+    startDate: new Date(2026, 1, 13, 12, 20),
+    endDate: new Date(2026, 1, 13, 14, 0),
+    assigneeId: [4],
+  },
+  {
+    id: 11,
+    text: 'Upgrade Server Hardware',
+    startDate: new Date(2026, 1, 13, 14, 30),
+    endDate: new Date(2026, 1, 13, 16, 0),
+    assigneeId: [2],
+  },
+];
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.html b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.html
new file mode 100644
index 000000000000..515568bf97e7
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
+  <head>
+    <title>DevExtreme Demo</title>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" />
+    <script src="../../../../node_modules/jquery/dist/jquery.min.js"></script>
+    <link rel="stylesheet" type="text/css" href="../../../../node_modules/devextreme-dist/css/dx.light.css" />
+
+    <script src="../../../../node_modules/devextreme-dist/js/dx.all.js"></script>
+    <script src="data.js"></script>
+    <link rel="stylesheet" type="text/css" href="styles.css" />
+    <script src="index.js"></script>
+  </head>
+  <body class="dx-viewport">
+    <div class="demo-container">
+      <div id="scheduler"></div>
+      <div class="options">
+        <div class="option">
+          <span>Overlapping Rule</span>
+          <div id="overlapping-rule"></div>
+        </div>
+      </div>
+    </div>
+  </body>
+</html>
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.js b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.js
new file mode 100644
index 000000000000..374a615d9f16
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/index.js
@@ -0,0 +1,212 @@
+$(() => {
+  let popup;
+  let form;
+  let showConflictError = false;
+  let overlappingRule = 'sameResource';
+
+  const scheduler = $('#scheduler').dxScheduler({
+    dataSource: data,
+    views: ['day', 'week', 'workWeek', 'month'],
+    currentView: 'week',
+    currentDate: new Date(2026, 1, 10),
+    startDayHour: 9,
+    endDayHour: 19,
+    height: 600,
+    showAllDayPanel: false,
+    allDayPanelMode: 'hidden',
+    resources: [{
+      fieldExpr: 'assigneeId',
+      dataSource: assignees,
+      valueExpr: 'id',
+      colorExpr: 'color',
+      icon: 'user',
+      allowMultiple: true,
+    }],
+    editing: {
+      popup: {
+        onInitialized: (e) => {
+          popup = e.component;
+        },
+        onHidden: () => {
+          setConflictError(false);
+          form?.updateData('assigneeId', []);
+        },
+      },
+      form: {
+        labelMode: 'hidden',
+        elementAttr: { class: 'hide-informer', id: 'form' },
+        onInitialized: (e) => {
+          form = e.component;
+
+          form.on('fieldDataChanged', (e) => {
+            if (showConflictError && ['startDate', 'endDate', 'assigneeId', 'recurrenceRule'].includes(e.dataField)) {
+              setConflictError(false);
+              form.validate();
+            }
+          });
+        },
+        items: [
+          {
+            name: 'conflictInformer',
+            template: () => $('<div>')
+              .addClass('conflict-informer')
+              .text('This time slot conflicts with another appointment.'),
+          },
+          {
+            name: 'mainGroup',
+            items: [
+              'subjectGroup',
+              'dateGroup',
+              'repeatGroup',
+              {
+                name: 'assigneeIdGroup',
+                items: [
+                  'assigneeIdIcon',
+                  {
+                    name: 'assigneeId',
+                    isRequired: true,
+                    editorOptions: {
+                      onValueChanged: (e) => {
+                        if (e.value.length > 1) {
+                          e.component.option('value', [e.value[e.value.length - 1]]);
+                        }
+                      },
+                      tagTemplate: (tagData) => $('<div />')
+                        .css('background-color', tagData.color)
+                        .css('border-color', tagData.color)
+                        .addClass('dx-tag-content')
+                        .append(
+                          $('<span />').text(tagData.text),
+                          $('<div />').addClass('dx-tag-remove-button'),
+                        ),
+                    },
+                  },
+                ],
+              },
+            ],
+          },
+          'recurrenceGroup',
+        ],
+        customizeItem: (item) => {
+          if (item.name === 'allDayEditor' || item.name === 'recurrenceEndEditor') {
+            item.label.visible = true;
+          } else if (item.name === 'subjectEditor') {
+            item.editorOptions.placeholder = 'Add title';
+          }
+
+          if (item.name === 'startTimeEditor' || item.name === 'endTimeEditor') {
+            item.validationRules = [
+              { type: 'required' },
+              {
+                type: 'custom',
+                message: 'Time conflict',
+                ignoreEmptyValue: true,
+                reevaluate: true,
+                validationCallback: () => !showConflictError,
+              },
+            ];
+          }
+        },
+      },
+    },
+    onAppointmentAdding(e) {
+      alertConflictIfNeeded(e, e.appointmentData);
+    },
+    onAppointmentUpdating(e) {
+      alertConflictIfNeeded(e, e.newData);
+    },
+  }).dxScheduler('instance');
+
+  function setConflictError(show) {
+    showConflictError = show;
+    form?.option('elementAttr.class', show ? '' : 'hide-informer');
+  }
+
+  function alertConflictIfNeeded(e, appointmentData) {
+    if (!detectConflict(appointmentData)) {
+      setConflictError(false);
+      return;
+    }
+
+    e.cancel = true;
+
+    if (popup?.option('visible')) {
+      setConflictError(true);
+      form.validate();
+    } else {
+      const dialog = DevExpress.ui.dialog.custom({
+        showTitle: false,
+        messageHtml: '<p id="conflict-dialog">This time slot conflicts with another appointment.</p>',
+        buttons: [{
+          type: 'default',
+          text: 'Close',
+          stylingMode: 'contained',
+          onClick: () => {
+            dialog.hide();
+          },
+        }],
+      });
+      dialog.show();
+    }
+  }
+
+  function getNextDay(date) {
+    const next = new Date(date);
+    next.setDate(next.getDate() + 1);
+    return next;
+  }
+
+  function getEndDate(occurrence) {
+    return occurrence.appointmentData.allDay
+      ? getNextDay(occurrence.startDate)
+      : occurrence.endDate;
+  }
+
+  function isOverlapping(a, b) {
+    const aEnd = getEndDate(a);
+    const bEnd = getEndDate(b);
+    if (a.startDate >= bEnd || b.startDate >= aEnd) return false;
+    if (overlappingRule === 'sameResource') {
+      return a.appointmentData.assigneeId[0] === b.appointmentData.assigneeId[0];
+    }
+    return true;
+  }
+
+  function detectConflict(newAppointment) {
+    const allAppointments = scheduler.getDataSource().items();
+    const startDate = new Date(newAppointment.startDate);
+    let endDate;
+    if (newAppointment.recurrenceRule) {
+      endDate = scheduler.getEndViewDate();
+    } else if (newAppointment.allDay) {
+      endDate = getNextDay(startDate);
+    } else {
+      endDate = new Date(newAppointment.endDate);
+    }
+
+    const existingOccurrences = scheduler
+      .getOccurrences(startDate, endDate, allAppointments)
+      .filter((occurrence) => occurrence.appointmentData.id !== newAppointment.id);
+
+    const newOccurrences = scheduler.getOccurrences(startDate, endDate, [newAppointment]);
+
+    return newOccurrences.some((newOccurrence) =>
+      existingOccurrences.some((existingOccurrence) =>
+        isOverlapping(newOccurrence, existingOccurrence),
+      ),
+    );
+  }
+
+  $('#overlapping-rule').dxSelectBox({
+    items: [
+      { value: 'sameResource', text: 'Allow across resources' },
+      { value: 'allResources', text: 'Disallow all overlaps' },
+    ],
+    valueExpr: 'value',
+    displayExpr: 'text',
+    value: 'sameResource',
+    onValueChanged(e) {
+      overlappingRule = e.value;
+    },
+  });
+});
diff --git a/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/styles.css b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/styles.css
new file mode 100644
index 000000000000..a9d28f566ae4
--- /dev/null
+++ b/apps/demos/Demos/Scheduler/ResolveTimeConflicts/jQuery/styles.css
@@ -0,0 +1,68 @@
+.dx-scheduler-appointment {
+  color: #242424;
+}
+
+.options {
+  padding: 20px;
+  background-color: rgba(191, 191, 191, 0.15);
+  margin-top: 20px;
+}
+
+.option {
+  margin-top: 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+#overlapping-rule {
+  width: 200px;
+}
+
+.hide-informer .dx-item:has(.conflict-informer) {
+  display: none !important;
+}
+
+.conflict-informer {
+  background-color: #FCEAE8;
+  color: #C50F1F;
+  font-size: 12px;
+  padding: 0 12px;
+  height: 36px;
+  line-height: 36px;
+  box-sizing: border-box;
+  margin-bottom: 8px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-overlay-content {
+  width: 280px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-content {
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-dialog-buttons {
+  padding-top: 0;
+  padding-bottom: 16px;
+}
+
+.dx-dialog:has(#conflict-dialog) .dx-toolbar-center,
+.dx-dialog:has(#conflict-dialog) .dx-button {
+  width: 100%;
+}
+
+.dx-scheduler-form-main-group .dx-item:last-child,
+.dx-scheduler-form-main-group .dx-item:last-child .dx-field-item-content {
+  overflow: visible;
+}
+
+#form .dx-scheduler-form-main-group,
+#form .dx-scheduler-form-recurrence-group {
+  padding-top: 0;
+}
+
+#form:not(.hide-informer) .dx-scheduler-form-recurrence-group.dx-scheduler-form-recurrence-group-hidden,
+#form:not(.hide-informer) .dx-scheduler-form-main-group.dx-scheduler-form-main-group-hidden {
+  top: 44px;
+}
diff --git a/apps/demos/menuMeta.json b/apps/demos/menuMeta.json
index ec74657b0427..3af24ca7a32b 100644
--- a/apps/demos/menuMeta.json
+++ b/apps/demos/menuMeta.json
@@ -3628,6 +3628,12 @@
                   "/Models/SampleData/PriorityResources.cs"
                 ],
                 "DemoType": "Web"
+              },
+              {
+                "Title": "Resolve Time Conflicts",
+                "Name": "ResolveTimeConflicts",
+                "Widget": "Scheduler",
+                "DemoType": "Web"
               }
             ]
           },
diff --git a/apps/demos/testing/etalons/Scheduler-ResolveTimeConflicts (fluent.blue.light).png b/apps/demos/testing/etalons/Scheduler-ResolveTimeConflicts (fluent.blue.light).png
new file mode 100644
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diff --git a/apps/demos/testing/etalons/Scheduler-ResolveTimeConflicts (material.blue.light).png b/apps/demos/testing/etalons/Scheduler-ResolveTimeConflicts (material.blue.light).png
new file mode 100644
index 000000000000..8331ef11e076
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