fix(web): show 1y ago instead of 0y ago for year-old comments

apps/web/__tests__/unit/activity-time-ago.test.ts

@@ -0,0 +1,34 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { formatTimeAgo } from "@/app/s/[videoId]/_components/tabs/Activity/utils";
+
+const NOW = new Date("2026-10-30T12:00:00Z");
+const daysAgo = (days: number) =>
+	new Date(NOW.getTime() - days * 24 * 60 * 60 * 1000);
+
+describe("formatTimeAgo", () => {
+	beforeEach(() => {
+		vi.useFakeTimers();
+		vi.setSystemTime(NOW);
+	});
+
+	afterEach(() => {
+		vi.useRealTimers();
+	});
+
+	it("shows months until twelve thirty-day months have passed", () => {
+		expect(formatTimeAgo(daysAgo(30))).toBe("1mo ago");
+		expect(formatTimeAgo(daysAgo(359))).toBe("11mo ago");
+	});
+
+	it("never shows zero years between 360 and 364 days", () => {
+		for (const days of [360, 362, 364]) {
+			expect(formatTimeAgo(daysAgo(days))).toBe("1y ago");
+		}
+	});
+
+	it("counts whole years after that", () => {
+		expect(formatTimeAgo(daysAgo(365))).toBe("1y ago");
+		expect(formatTimeAgo(daysAgo(729))).toBe("1y ago");
+		expect(formatTimeAgo(daysAgo(730))).toBe("2y ago");
+	});
+});

apps/web/app/s/[videoId]/_components/tabs/Activity/utils.ts

@@ -27,6 +27,7 @@ export const formatTimeAgo = (date: Date) => {
 	const diffInMonths = Math.floor(diffInDays / 30);
 	if (diffInMonths < 12) return `${diffInMonths}mo ago`;
 
-	const diffInYears = Math.floor(diffInDays / 365);
+	// 12 thirty-day months is 360 days, five days short of a 365-day year.
+	const diffInYears = Math.max(1, Math.floor(diffInDays / 365));
 	return `${diffInYears}y ago`;
 };