diff --git a/src/features/schedule/components/ScheduleDetailsPage.test.tsx b/src/features/schedule/components/ScheduleDetailsPage.test.tsx
index 6cc2db81..3b932f70 100644
--- a/src/features/schedule/components/ScheduleDetailsPage.test.tsx
+++ b/src/features/schedule/components/ScheduleDetailsPage.test.tsx
@@ -60,8 +60,14 @@ vi.mock("@/i18n/resolver.js", () => ({
 }));
 
 // Mutable for individual test overrides
-let mockScheduleDetailsResult: { flights: unknown[]; loading: boolean; error: unknown } = {
+let mockScheduleDetailsResult: {
+  flights: unknown[];
+  daysOfFlight: string[];
+  loading: boolean;
+  error: unknown;
+} = {
   flights: [],
+  daysOfFlight: [],
   loading: true,
   error: null,
 };
@@ -145,7 +151,9 @@ vi.mock("@/features/online-board/components/FlightsMiniList/index.js", () => ({
 }));
 
 vi.mock("@/features/online-board/components/DayTabs/index.js", () => ({
-  DayTabs: () => <div data-testid="day-tabs" />,
+  DayTabs: ({ availableDates }: { availableDates: string[] }) => (
+    <div data-testid="day-tabs" data-available-dates={availableDates.join(",")} />
+  ),
 }));
 
 vi.mock("@/ui/flights/FlightCard.js", () => ({
@@ -187,7 +195,7 @@ const flightId: IScheduleFlightId = {
 describe("ScheduleDetailsPage breadcrumbs", () => {
   beforeEach(() => {
     mockSearchParamsGet = () => null;
-    mockScheduleDetailsResult = { flights: [], loading: true, error: null };
+    mockScheduleDetailsResult = { flights: [], daysOfFlight: [], loading: true, error: null };
   });
 
   it("shows 1-item trail when no ?request= param (share-link)", () => {
@@ -253,7 +261,7 @@ describe("ScheduleDetailsPage structure (§4.1.16.1 + §4.1.16.2 + §4.1.16.3)",
   beforeEach(() => {
     mockSearchParamsGet = () => null;
     // Reset to loading state (breadcrumb tests rely on this)
-    mockScheduleDetailsResult = { flights: [], loading: true, error: null };
+    mockScheduleDetailsResult = { flights: [], daysOfFlight: [], loading: true, error: null };
     // The new ScheduleFlightsMiniList scrolls the highlighted row into
     // view on mount; JSDOM doesn't ship `scrollIntoView`, so stub it.
     Element.prototype.scrollIntoView = vi.fn();
@@ -288,6 +296,7 @@ describe("ScheduleDetailsPage structure (§4.1.16.1 + §4.1.16.2 + §4.1.16.3)",
           },
         },
       ],
+      daysOfFlight: ["20260515", "20260516"],
       loading: false,
       error: null,
     };
@@ -333,6 +342,7 @@ describe("ScheduleDetailsPage structure (§4.1.16.1 + §4.1.16.2 + §4.1.16.3)",
           },
         },
       ],
+      daysOfFlight: ["20260515", "20260516"],
       loading: false,
       error: null,
     };
@@ -345,6 +355,9 @@ describe("ScheduleDetailsPage structure (§4.1.16.1 + §4.1.16.2 + §4.1.16.3)",
     );
     // Success state renders DayTabs in stickyContent (Schedule window = +330 days)
     expect(screen.getByTestId("day-tabs")).toBeTruthy();
+    expect(screen.getByTestId("day-tabs").getAttribute("data-available-dates")).toBe(
+      "20260515,20260516",
+    );
   });
 
   it("4.1.16.1-R4: back link navigates to scheduleHref (success state)", () => {
@@ -377,6 +390,7 @@ describe("ScheduleDetailsPage structure (§4.1.16.1 + §4.1.16.2 + §4.1.16.3)",
           },
         },
       ],
+      daysOfFlight: ["20260515", "20260516"],
       loading: false,
       error: null,
     };
diff --git a/src/features/schedule/components/ScheduleDetailsPage.tsx b/src/features/schedule/components/ScheduleDetailsPage.tsx
index e2fb633b..5548f06b 100644
--- a/src/features/schedule/components/ScheduleDetailsPage.tsx
+++ b/src/features/schedule/components/ScheduleDetailsPage.tsx
@@ -95,7 +95,7 @@ export const ScheduleDetailsPage: FC<ScheduleDetailsPageProps> = ({
     arrival: "",
   };
 
-  const { flights, loading, error } = useScheduleDetails(detailsParams);
+  const { flights, daysOfFlight, loading, error } = useScheduleDetails(detailsParams);
 
   const scheduleHref = `/${locale}/schedule`;
 
@@ -382,7 +382,7 @@ export const ScheduleDetailsPage: FC<ScheduleDetailsPageProps> = ({
         // TZ §4.1.16.3 R22-R28: day tabs (Schedule window: [-1, +330] from today)
         <DayTabs
           selectedDate={selectedDate}
-          availableDates={[]}
+          availableDates={daysOfFlight}
           daysBefore={scheduleSearchFrom}
           daysAfter={scheduleSearchTo}
           locale={locale}
diff --git a/src/features/schedule/hooks/useScheduleDetails.ts b/src/features/schedule/hooks/useScheduleDetails.ts
index a20cf461..763a3ad0 100644
--- a/src/features/schedule/hooks/useScheduleDetails.ts
+++ b/src/features/schedule/hooks/useScheduleDetails.ts
@@ -21,6 +21,7 @@ export interface UseScheduleDetailsParams {
 
 export interface UseScheduleDetailsResult {
   flights: ISimpleFlight[];
+  daysOfFlight: string[];
   loading: boolean;
   error: ApiError | null;
 }
@@ -34,6 +35,7 @@ export function useScheduleDetails(
 ): UseScheduleDetailsResult {
   const client = useApiClient();
   const [flights, setFlights] = useState<ISimpleFlight[]>([]);
+  const [daysOfFlight, setDaysOfFlight] = useState<string[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<ApiError | null>(null);
 
@@ -53,6 +55,7 @@ export function useScheduleDetails(
       .then((response) => {
         if (!cancelled) {
           setFlights(response.data.routes);
+          setDaysOfFlight(response.data.daysOfFlight ?? []);
           setLoading(false);
         }
       })
@@ -68,5 +71,5 @@ export function useScheduleDetails(
     };
   }, [client, flightsKey, datesKey, params.departure, params.arrival]);
 
-  return { flights, loading, error };
+  return { flights, daysOfFlight, loading, error };
 }
diff --git a/tests/e2e/schedule-details-day-tabs-operating-days.spec.ts b/tests/e2e/schedule-details-day-tabs-operating-days.spec.ts
new file mode 100644
index 00000000..da07e7ac
--- /dev/null
+++ b/tests/e2e/schedule-details-day-tabs-operating-days.spec.ts
@@ -0,0 +1,61 @@
+import fs from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { test, expect } from "./fixtures/console-gate";
+import { routeAppSettingsFixture } from "./helpers/api-fixtures";
+
+const FIXTURE_DIR = path.resolve(
+  path.dirname(fileURLToPath(import.meta.url)),
+  "../fixtures/api",
+);
+
+const URL =
+  "/ru-ru/schedule/KJA/SU6837-20260519/MJZ?request=schedule-route-KJA-MJZ-20260518-20260524-C0";
+
+test("TIRREDESIGN-26: schedule details day tabs disable non-operating flight dates", async ({
+  page,
+  consoleMessages,
+}) => {
+  await routeAppSettingsFixture(page);
+  await page.route("**/api/flights/v1.1/*/schedule/details?**", async (route) => {
+    const source = JSON.parse(
+      fs.readFileSync(path.join(FIXTURE_DIR, "schedule-details-vvo-mjz.json"), "utf8"),
+    ) as {
+      data: {
+        routes: Array<{
+          flightId: { carrier: string; flightNumber: string; date: string };
+        }>;
+        partners: string[];
+      };
+    };
+    const su6837 = source.data.routes.find(
+      (flight) =>
+        flight.flightId.carrier === "SU" &&
+        flight.flightId.flightNumber === "6837" &&
+        flight.flightId.date === "2026-05-19",
+    );
+    expect(su6837).toBeTruthy();
+    await route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({
+        data: {
+          partners: [],
+          routes: su6837 ? [su6837] : [],
+          daysOfFlight: ["20260519", "20260523"],
+        },
+      }),
+    });
+  });
+
+  await page.goto(URL);
+  await expect(page.getByTestId("day-tabs")).toBeVisible({ timeout: 15000 });
+  await expect(page.getByTestId("day-tab-20260519")).toBeEnabled();
+
+  await page.getByTestId("day-tabs-next").click();
+  const nonOperatingFriday = page.getByTestId("day-tab-20260522");
+  await expect(nonOperatingFriday).toBeDisabled();
+  await expect(page.getByTestId("day-tab-20260523")).toBeEnabled();
+
+  await expect(page.getByTestId("schedule-details-not-found")).toHaveCount(0);
+});