diff --git a/app/features/tournament/TournamentRepository.server.ts b/app/features/tournament/TournamentRepository.server.ts
index 2c439f150..68c012a76 100644
--- a/app/features/tournament/TournamentRepository.server.ts
+++ b/app/features/tournament/TournamentRepository.server.ts
@@ -553,7 +553,7 @@ export function findAllBetweenTwoTimestamps({
 		.select(["Tournament.id as tournamentId"])
 		.where(
 			"CalendarEventDate.startTime",
-			">=",
+			">",
 			dateToDatabaseTimestamp(startTime),
 		)
 		.where(
diff --git a/app/routines/notifyCheckInStart.test.ts b/app/routines/notifyCheckInStart.test.ts
new file mode 100644
index 000000000..77eebd613
--- /dev/null
+++ b/app/routines/notifyCheckInStart.test.ts
@@ -0,0 +1,176 @@
+import { add } from "date-fns";
+import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
+import * as CalendarRepository from "~/features/calendar/CalendarRepository.server";
+import { clearAllTournamentDataCache } from "~/features/tournament-bracket/core/Tournament.server";
+import { dateToDatabaseTimestamp } from "~/utils/dates";
+import { dbInsertUsers, dbReset } from "~/utils/Test";
+import { NotifyCheckInStartRoutine } from "./notifyCheckInStart";
+
+const { mockNotify } = vi.hoisted(() => ({
+	mockNotify: vi.fn(),
+}));
+
+vi.mock("~/features/notifications/core/notify.server", () => ({
+	notify: mockNotify,
+}));
+
+async function createTestTournament({
+	name,
+	startTime,
+	authorId = 1,
+	discordInviteCode = "test-discord",
+}: {
+	name: string;
+	startTime: Date;
+	authorId?: number;
+	discordInviteCode?: string;
+}) {
+	return CalendarRepository.create({
+		isFullTournament: true,
+		authorId,
+		badges: [],
+		bracketUrl: "https://example.com/bracket",
+		description: null,
+		discordInviteCode,
+		deadlines: "DEFAULT",
+		name,
+		organizationId: null,
+		rules: null,
+		startTimes: [dateToDatabaseTimestamp(startTime)],
+		tags: null,
+		bracketProgression: [
+			{
+				name: "Bracket",
+				type: "single_elimination",
+				requiresCheckIn: false,
+				settings: {
+					thirdPlaceMatch: false,
+				},
+			},
+		],
+		mapPickingStyle: "TO",
+		mapPoolMaps: ([1, 2, 3, 4, 5] as const).map((id) => ({
+			mode: "SZ",
+			stageId: id,
+		})),
+	});
+}
+
+describe("NotifyCheckInStartRoutine", () => {
+	beforeEach(async () => {
+		vi.useFakeTimers();
+		vi.setSystemTime(new Date("2025-01-15T12:00:00Z"));
+		dbReset();
+		clearAllTournamentDataCache();
+		await dbInsertUsers(5);
+		mockNotify.mockClear();
+	});
+
+	afterEach(() => {
+		vi.useRealTimers();
+	});
+
+	test("sends notification for tournament starting exactly 1 hour from now", async () => {
+		const now = new Date();
+		const oneHourFromNow = add(now, { hours: 1 });
+
+		await createTestTournament({
+			name: "Tournament 1 Hour Away",
+			startTime: oneHourFromNow,
+		});
+
+		await NotifyCheckInStartRoutine.run();
+
+		expect(mockNotify).toHaveBeenCalledTimes(1);
+		expect(mockNotify).toHaveBeenCalledWith(
+			expect.objectContaining({
+				notification: expect.objectContaining({
+					type: "TO_CHECK_IN_OPENED",
+					meta: expect.objectContaining({
+						tournamentName: "Tournament 1 Hour Away",
+					}),
+				}),
+			}),
+		);
+	});
+
+	test("does NOT send notification for tournament starting exactly now", async () => {
+		const now = new Date();
+
+		await createTestTournament({
+			name: "Tournament Starting Now",
+			startTime: now,
+		});
+
+		await NotifyCheckInStartRoutine.run();
+
+		expect(mockNotify).not.toHaveBeenCalled();
+	});
+
+	test("sends notification for tournament starting 30 minutes from now", async () => {
+		const now = new Date();
+		const thirtyMinutesFromNow = add(now, { minutes: 30 });
+
+		await createTestTournament({
+			name: "Tournament 30 Minutes Away",
+			startTime: thirtyMinutesFromNow,
+		});
+
+		await NotifyCheckInStartRoutine.run();
+
+		expect(mockNotify).toHaveBeenCalledTimes(1);
+		expect(mockNotify).toHaveBeenCalledWith(
+			expect.objectContaining({
+				notification: expect.objectContaining({
+					type: "TO_CHECK_IN_OPENED",
+					meta: expect.objectContaining({
+						tournamentName: "Tournament 30 Minutes Away",
+					}),
+				}),
+			}),
+		);
+	});
+
+	test("does NOT send notification for tournament starting more than 1 hour from now", async () => {
+		const now = new Date();
+		const oneAndHalfHoursFromNow = add(now, { hours: 1, minutes: 30 });
+
+		await createTestTournament({
+			name: "Tournament 1.5 Hours Away",
+			startTime: oneAndHalfHoursFromNow,
+		});
+
+		await NotifyCheckInStartRoutine.run();
+
+		expect(mockNotify).not.toHaveBeenCalled();
+	});
+
+	test("sends notifications for multiple tournaments in the time window", async () => {
+		const now = new Date();
+		const thirtyMinutesFromNow = add(now, { minutes: 30 });
+		const fortyFiveMinutesFromNow = add(now, { minutes: 45 });
+
+		await createTestTournament({
+			name: "Tournament A",
+			startTime: thirtyMinutesFromNow,
+			discordInviteCode: "test-discord-1",
+		});
+
+		await createTestTournament({
+			name: "Tournament B",
+			startTime: fortyFiveMinutesFromNow,
+			authorId: 2,
+			discordInviteCode: "test-discord-2",
+		});
+
+		await NotifyCheckInStartRoutine.run();
+
+		expect(mockNotify).toHaveBeenCalledTimes(2);
+
+		const tournamentNames = mockNotify.mock.calls.map(
+			(call) => call[0].notification.meta.tournamentName,
+		);
+		expect(tournamentNames).toContain("Tournament A");
+		expect(tournamentNames).toContain("Tournament B");
+	});
+});