diff --git a/src/webparts/stroyBot/pages/works/useWorkEditor.ts b/src/webparts/stroyBot/pages/works/useWorkEditor.ts
index 86abfcc..73b7f3c 100644
--- a/src/webparts/stroyBot/pages/works/useWorkEditor.ts
+++ b/src/webparts/stroyBot/pages/works/useWorkEditor.ts
@@ -1,6 +1,6 @@
 import * as React from 'react';
 import { buildWorkBody, IWorksRepository } from './worksRepository';
-import { isTitleValid, needsClearParent, resetFormKeepParent, workToForm } from './worksRules';
+import { isDateRangeValid, isTitleValid, needsClearParent, resetFormKeepParent, workToForm } from './worksRules';
 import { EMPTY_WORK_FORM, IWork, IWorkForm, WorkModalMode } from './worksTypes';
 import { WORKS_TEXTS } from './texts';
 
@@ -63,6 +63,11 @@ export function useWorkEditor({ repository, objectId, reloadWorks }: IEditorDeps
       titleInputRef.current?.focus();
       return;
     }
+    // В старом stroy-bot-works проверки не было — исправлено при ручной проверке (T-WRK).
+    if (!isDateRangeValid(form)) {
+      setState((prev) => ({ ...prev, isTitleInvalid: false, saveError: WORKS_TEXTS.modal.dateRangeError }));
+      return;
+    }
     setState((prev) => ({ ...prev, isTitleInvalid: false, isSaving: true, saveError: undefined }));
     try {
       const parentNavProperty = form.parentId.trim() ? await repository.getParentNavProperty() : '';
diff --git a/src/webparts/stroyBot/pages/works/worksRules.test.ts b/src/webparts/stroyBot/pages/works/worksRules.test.ts
index 2c04c98..e5df3b4 100644
--- a/src/webparts/stroyBot/pages/works/worksRules.test.ts
+++ b/src/webparts/stroyBot/pages/works/worksRules.test.ts
@@ -2,6 +2,7 @@ import {
   buildWorkTree,
   formatDateRange,
   formatVolume,
+  isDateRangeValid,
   isTitleValid,
   needsClearParent,
   parentOptions,
@@ -80,6 +81,13 @@ describe('форма', () => {
     });
   });
 
+  it('окончание не раньше начала; пустые даты не проверяются (баг старого кода исправлен)', () => {
+    expect(isDateRangeValid({ ...EMPTY_WORK_FORM, start: '2026-10-19', finish: '2026-10-16' })).toBe(false);
+    expect(isDateRangeValid({ ...EMPTY_WORK_FORM, start: '2026-10-19', finish: '2026-10-19' })).toBe(true);
+    expect(isDateRangeValid({ ...EMPTY_WORK_FORM, start: '2026-10-19', finish: '' })).toBe(true);
+    expect(isDateRangeValid({ ...EMPTY_WORK_FORM, start: '', finish: '2026-10-16' })).toBe(true);
+  });
+
   it('наименование обязательно (пробелы не считаются)', () => {
     expect(isTitleValid({ ...EMPTY_WORK_FORM, title: '   ' })).toBe(false);
     expect(isTitleValid({ ...EMPTY_WORK_FORM, title: 'Бетон' })).toBe(true);
diff --git a/src/webparts/stroyBot/pages/works/worksRules.ts b/src/webparts/stroyBot/pages/works/worksRules.ts
index 1ec03a5..52dc0df 100644
--- a/src/webparts/stroyBot/pages/works/worksRules.ts
+++ b/src/webparts/stroyBot/pages/works/worksRules.ts
@@ -84,6 +84,11 @@ export function resetFormKeepParent(form: IWorkForm): IWorkForm {
   return { title: '', unit: '', volume: '', parentId: form.parentId, start: '', finish: '' };
 }
 
+/** Окончание не раньше начала (даты YYYY-MM-DD сравниваются строками). Пустые даты не проверяются. */
+export function isDateRangeValid(form: IWorkForm): boolean {
+  return !form.start || !form.finish || form.start <= form.finish;
+}
+
 export function isTitleValid(form: IWorkForm): boolean {
   return form.title.trim() !== '';
 }