diff --git a/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.test.ts b/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.test.ts
new file mode 100644
index 00000000..755326eb
--- /dev/null
+++ b/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.test.ts
@@ -0,0 +1,68 @@
+import { describe, it, expect } from "vitest";
+import { canBuyTicket } from "./buyTicketVisibility.js";
+import type { ISimpleFlight, FlightStatus } from "../../../types.js";
+
+function makeFlight(status: FlightStatus, depUtc: string): ISimpleFlight {
+  return {
+    id: "SU0022-X",
+    routeType: "Direct",
+    flyingTime: "1h",
+    status,
+    flightId: { carrier: "SU", flightNumber: "0022", suffix: "", date: "20260417" },
+    operatingBy: { carrier: "SU", flightNumber: "0022" },
+    leg: {
+      arrival: {
+        scheduled: { airport: "", airportCode: "", city: "", cityCode: "", countryCode: "" },
+        latest: { airport: "", airportCode: "", city: "", cityCode: "", countryCode: "" },
+        dispatch: "", gate: "", terminal: "",
+        times: { scheduledArrival: { dayChange: { value: 0, title: "" }, local: "", localTime: "", tzOffset: 0, utc: "" } },
+      },
+      dayChange: 0,
+      departure: {
+        scheduled: { airport: "", airportCode: "", city: "", cityCode: "", countryCode: "" },
+        latest: { airport: "", airportCode: "", city: "", cityCode: "", countryCode: "" },
+        dispatch: "", gate: "", terminal: "", checkingStatus: "Scheduled", parkingStand: "",
+        times: { scheduledDeparture: { dayChange: { value: 0, title: "" }, local: "", localTime: "", tzOffset: 0, utc: depUtc } },
+      },
+      equipment: {},
+      flags: { checkinAvailable: false, returnToAirport: false, routeChanged: false },
+      flyingTime: "1h",
+      index: 0,
+      operatingBy: {},
+      status,
+      updated: "",
+    },
+  } as ISimpleFlight;
+}
+
+describe("canBuyTicket", () => {
+  it("returns false when status is Cancelled", () => {
+    const now = new Date("2026-04-17T10:00:00Z");
+    expect(canBuyTicket(makeFlight("Cancelled", "2026-04-18T10:00:00Z"), now, 2, 72)).toBe(false);
+  });
+
+  it("returns false when status is InFlight", () => {
+    const now = new Date("2026-04-17T10:00:00Z");
+    expect(canBuyTicket(makeFlight("InFlight", "2026-04-18T10:00:00Z"), now, 2, 72)).toBe(false);
+  });
+
+  it("returns true when now is in window (24h before)", () => {
+    const now = new Date("2026-04-17T10:00:00Z");
+    expect(canBuyTicket(makeFlight("Scheduled", "2026-04-18T10:00:00Z"), now, 2, 72)).toBe(true);
+  });
+
+  it("returns false when now is too close (<minHours before)", () => {
+    const now = new Date("2026-04-17T09:00:00Z");
+    expect(canBuyTicket(makeFlight("Scheduled", "2026-04-17T10:00:00Z"), now, 2, 72)).toBe(false);
+  });
+
+  it("returns false when now is too far (>maxHours before)", () => {
+    const now = new Date("2026-04-17T00:00:00Z");
+    expect(canBuyTicket(makeFlight("Scheduled", "2026-04-25T00:00:00Z"), now, 2, 72)).toBe(false);
+  });
+
+  it("returns false when UTC departure is empty", () => {
+    const now = new Date();
+    expect(canBuyTicket(makeFlight("Scheduled", ""), now, 2, 72)).toBe(false);
+  });
+});
diff --git a/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.ts b/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.ts
new file mode 100644
index 00000000..c299dc2b
--- /dev/null
+++ b/src/features/online-board/components/BoardDetailsHeader/visibility/buyTicketVisibility.ts
@@ -0,0 +1,30 @@
+import { parseISO, subHours, isAfter, isBefore } from "date-fns";
+import type { ISimpleFlight } from "../../../types.js";
+
+/**
+ * Buy Ticket button is visible when:
+ * - flight is NOT Cancelled or InFlight
+ * - now falls within [departure - maxHours, departure - minHours]
+ */
+export function canBuyTicket(
+  flight: ISimpleFlight,
+  now: Date,
+  minHours: number,
+  maxHours: number,
+): boolean {
+  if (flight.status === "Cancelled" || flight.status === "InFlight") return false;
+
+  const leg = flight.routeType === "Direct" ? flight.leg : flight.legs[0];
+  if (!leg) return false;
+
+  const depUtc = leg.departure.times.scheduledDeparture.utc;
+  if (!depUtc) return false;
+
+  const departure = parseISO(depUtc);
+  if (isNaN(departure.getTime())) return false;
+
+  const showFrom = subHours(departure, maxHours);
+  const showUntil = subHours(departure, minHours);
+
+  return isAfter(now, showFrom) && isBefore(now, showUntil);
+}