diff --git a/packages/graphql/api/slots.test.js b/packages/graphql/api/slots.test.js
index 18735e6..9049ee1 100644
--- a/packages/graphql/api/slots.test.js
+++ b/packages/graphql/api/slots.test.js
@@ -247,7 +247,7 @@ describe('SlotsService', () => {
 
       const result = slotsService.updateSlot(variablesWithMissingStart);
 
-      await expect(result).rejects.toThrow(ERRORS.INVALID_TIME);
+      await expect(result).rejects.toThrow(ERRORS.MISSING_DATETIME_START);
     });
 
     it('should throw error when datetime_end is missing', async () => {
@@ -284,7 +284,7 @@ describe('SlotsService', () => {
 
       const result = slotsService.updateSlot(variablesWithMissingEnd);
 
-      await expect(result).rejects.toThrow(ERRORS.INVALID_TIME);
+      await expect(result).rejects.toThrow(ERRORS.MISSING_DATETIME_END);
     });
 
     it('should throw error when datetime_end is before datetime_start', async () => {
@@ -606,76 +606,6 @@ describe('SlotsService', () => {
 
       await expect(result).resolves.toBe(mockMutationResult.data);
     });
-
-    it('should use existing slot times when only datetime_start is provided', async () => {
-      const variablesWithOnlyStart = {
-        data: {
-          datetime_start: '2024-01-01T09:00:00Z',
-        },
-        documentId: 'slot-123',
-      };
-
-      const mockMutate = vi.fn().mockResolvedValue(mockMutationResult);
-      const mockQuery = vi.fn().mockImplementation(({ query }) => {
-        if (query === GQL.GetCustomerDocument) {
-          return Promise.resolve(mockGetCustomerResult);
-        }
-
-        if (query === GQL.GetSlotDocument) {
-          return Promise.resolve(mockGetSlotResult);
-        }
-
-        if (query === GQL.GetSlotsDocument) {
-          return Promise.resolve({ data: { slots: [] } });
-        }
-
-        return Promise.resolve({ data: {} });
-      });
-
-      mockGetClientWithToken.mockResolvedValue({
-        mutate: mockMutate,
-        query: mockQuery,
-      });
-
-      const result = slotsService.updateSlot(variablesWithOnlyStart);
-
-      await expect(result).resolves.toBe(mockMutationResult.data);
-    });
-
-    it('should use existing slot times when only datetime_end is provided', async () => {
-      const variablesWithOnlyEnd = {
-        data: {
-          datetime_end: '2024-01-01T12:00:00Z',
-        },
-        documentId: 'slot-123',
-      };
-
-      const mockMutate = vi.fn().mockResolvedValue(mockMutationResult);
-      const mockQuery = vi.fn().mockImplementation(({ query }) => {
-        if (query === GQL.GetCustomerDocument) {
-          return Promise.resolve(mockGetCustomerResult);
-        }
-
-        if (query === GQL.GetSlotDocument) {
-          return Promise.resolve(mockGetSlotResult);
-        }
-
-        if (query === GQL.GetSlotsDocument) {
-          return Promise.resolve({ data: { slots: [] } });
-        }
-
-        return Promise.resolve({ data: {} });
-      });
-
-      mockGetClientWithToken.mockResolvedValue({
-        mutate: mockMutate,
-        query: mockQuery,
-      });
-
-      const result = slotsService.updateSlot(variablesWithOnlyEnd);
-
-      await expect(result).resolves.toBe(mockMutationResult.data);
-    });
   });
 
   describe('deleteSlot', () => {
diff --git a/packages/graphql/api/slots.ts b/packages/graphql/api/slots.ts
index 86df0b0..d0c682a 100644
--- a/packages/graphql/api/slots.ts
+++ b/packages/graphql/api/slots.ts
@@ -11,7 +11,8 @@ import dayjs from 'dayjs';
 export const ERRORS = {
   HAS_ORDERS: 'Слот имеет активные заказы',
   INVALID_TIME: 'Некорректное время',
-  MISSING_DATE: 'Не указана дата',
+  MISSING_DATETIME_END: 'Не указана дата окончания',
+  MISSING_DATETIME_START: 'Не указана дата начала',
   MISSING_SERVICE_ID: 'Не указана услуга',
   NO_PERMISSION: 'Нет доступа',
   OVERLAPPING_TIME: 'Время пересекается с другими слотами',
@@ -75,7 +76,7 @@ export class SlotsService extends BaseService {
     variables: VariablesOf<typeof GQL.GetSlotsDocument>,
     context: { service: GQL.ServiceFiltersInput },
   ) {
-    if (!variables.filters?.datetime_start) throw new Error(ERRORS.MISSING_DATE);
+    if (!variables.filters?.datetime_start) throw new Error(ERRORS.MISSING_DATETIME_START);
     if (!context?.service?.documentId?.eq) throw new Error(ERRORS.MISSING_SERVICE_ID);
 
     const { query } = await getClientWithToken();
@@ -181,20 +182,15 @@ export class SlotsService extends BaseService {
 
     if (!slot) throw new Error(ERRORS.SLOT_NOT_FOUND);
 
-    const isTimeChanging = variables?.data?.datetime_start || variables?.data?.datetime_end;
+    const datetime_start = variables.data.datetime_start;
+    const datetime_end = variables.data.datetime_end;
+
+    const isTimeChanging = datetime_start || datetime_end;
 
     if (!isTimeChanging) return;
 
-    let datetime_start = variables.data.datetime_start;
-    let datetime_end = variables.data.datetime_end;
-
-    if (!datetime_start) datetime_start = slot?.datetime_start;
-    if (!datetime_end) datetime_end = slot?.datetime_end;
-
-    // Проверка: оба времени должны быть определены
-    if (!datetime_start || !datetime_end) {
-      throw new Error(ERRORS.INVALID_TIME);
-    }
+    if (!datetime_start) throw new Error(ERRORS.MISSING_DATETIME_START);
+    if (!datetime_end) throw new Error(ERRORS.MISSING_DATETIME_END);
 
     // Проверка валидности времени
     if (new Date(datetime_end) <= new Date(datetime_start)) {