diff --git a/Docs/Tasks.md b/Docs/Tasks.md
index e99ff34..9f4ae19 100644
--- a/Docs/Tasks.md
+++ b/Docs/Tasks.md
@@ -331,7 +331,11 @@ Rewrite the four hooks listed above as thin wrappers around `useListData`.
 
 ---
 
-### TASK-017 — Move `source` derivation out of page components
+### TASK-017 — Move `source` derivation out of page components (done)
+
+**Where fixed:** `frontend/src/utils/queryUtils.ts`, `frontend/src/pages/DashboardPage.tsx`, `frontend/src/pages/MapPage.tsx`
+
+**Summary:** Added `getDataSource` to `frontend/src/utils/queryUtils.ts` and replaced inline `timeRange === "24h"` ternaries with the shared function in both dashboard and map pages.
 
 **Where found:** `frontend/src/pages/DashboardPage.tsx` and `frontend/src/pages/MapPage.tsx` both contain the identical line:
 ```ts
diff --git a/frontend/src/pages/DashboardPage.tsx b/frontend/src/pages/DashboardPage.tsx
index d0a235b..a7cd5ca 100644
--- a/frontend/src/pages/DashboardPage.tsx
+++ b/frontend/src/pages/DashboardPage.tsx
@@ -17,6 +17,7 @@ import { TopCountriesBarChart } from "../components/TopCountriesBarChart";
 import { TopCountriesPieChart } from "../components/TopCountriesPieChart";
 import { useCommonSectionStyles } from "../components/commonStyles";
 import { useDashboardCountryData } from "../hooks/useDashboardCountryData";
+import { getDataSource } from "../utils/queryUtils";
 import type { BanOriginFilter, TimeRange } from "../types/ban";
 
 
@@ -71,7 +72,7 @@ export function DashboardPage(): React.JSX.Element {
   const [timeRange, setTimeRange] = useState<TimeRange>("24h");
   const [originFilter, setOriginFilter] = useState<BanOriginFilter>("all");
 
-  const source = timeRange === "24h" ? "fail2ban" : "archive";
+  const source = getDataSource(timeRange);
 
   const { countries, countryNames, isLoading: countryLoading, error: countryError, reload: reloadCountry } =
     useDashboardCountryData(timeRange, originFilter, source);
diff --git a/frontend/src/pages/MapPage.tsx b/frontend/src/pages/MapPage.tsx
index 46362cf..a62ef7d 100644
--- a/frontend/src/pages/MapPage.tsx
+++ b/frontend/src/pages/MapPage.tsx
@@ -25,6 +25,7 @@ import { WorldMap } from "../components/WorldMap";
 import { useMapData } from "../hooks/useMapData";
 import { useMapColorThresholds } from "../hooks/useMapColorThresholds";
 import { MapBansTable } from "./map/MapBansTable";
+import { getDataSource } from "../utils/queryUtils";
 import type { TimeRange } from "../types/map";
 import type { BanOriginFilter } from "../types/ban";
 
@@ -96,7 +97,7 @@ export function MapPage(): React.JSX.Element {
   const [page, setPage] = useState<number>(1);
   const [pageSize, setPageSize] = useState<number>(100);
 
-  const source = range === "24h" ? "fail2ban" : "archive";
+  const source = getDataSource(range);
 
   const { countries, countryNames, bans, total, loading, error, refresh } =
     useMapData(range, originFilter, source, selectedCountry ?? undefined);
diff --git a/frontend/src/utils/__tests__/queryUtils.test.ts b/frontend/src/utils/__tests__/queryUtils.test.ts
index cf8214d..4de3151 100644
--- a/frontend/src/utils/__tests__/queryUtils.test.ts
+++ b/frontend/src/utils/__tests__/queryUtils.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { areHistoryQueriesEqual } from "../queryUtils";
+import { areHistoryQueriesEqual, getDataSource } from "../queryUtils";
 import type { HistoryQuery } from "../../types/history";
 
 describe("areHistoryQueriesEqual", () => {
@@ -38,3 +38,15 @@ describe("areHistoryQueriesEqual", () => {
     ).toBe(false);
   });
 });
+
+describe("getDataSource", () => {
+  it("returns fail2ban for the 24h range", () => {
+    expect(getDataSource("24h")).toBe("fail2ban");
+  });
+
+  it("returns archive for ranges other than 24h", () => {
+    expect(getDataSource("7d")).toBe("archive");
+    expect(getDataSource("30d")).toBe("archive");
+    expect(getDataSource("365d")).toBe("archive");
+  });
+});
diff --git a/frontend/src/utils/queryUtils.ts b/frontend/src/utils/queryUtils.ts
index 6f757f6..21eaeed 100644
--- a/frontend/src/utils/queryUtils.ts
+++ b/frontend/src/utils/queryUtils.ts
@@ -3,6 +3,7 @@
  */
 
 import type { HistoryQuery } from "../types/history";
+import type { TimeRange } from "../types/ban";
 
 /**
  * Compare two history query objects for semantic equality.
@@ -25,3 +26,13 @@ export function areHistoryQueriesEqual(
     a.page_size === b.page_size
   );
 }
+
+/**
+ * Return the data source for the given dashboard time range.
+ *
+ * @param range - The selected time range.
+ * @returns The backend source to query.
+ */
+export function getDataSource(range: TimeRange): "fail2ban" | "archive" {
+  return range === "24h" ? "fail2ban" : "archive";
+}