diff --git a/src/middleware/rateLimit.js b/src/middleware/rateLimit.js
new file mode 100644
index 0000000..684628c
--- /dev/null
+++ b/src/middleware/rateLimit.js
@@ -0,0 +1,18 @@
+// Fixed-window rate limiter. Windows start at multiples of windowMs.
+export function createRateLimiter({ limit, windowMs, now = Date.now }) {
+  let window = null;
+  let counts = new Map();
+
+  return function allow(key) {
+    const current = Math.floor(now() / windowMs);
+    if (current !== window) {
+      // New window: drop counts from the previous one so the map doesn't grow forever.
+      window = current;
+      counts = new Map();
+    }
+    const used = counts.get(key) ?? 0;
+    if (used >= limit) return false;
+    counts.set(key, used + 1);
+    return true;
+  };
+}
diff --git a/src/routes/notes.js b/src/routes/notes.js
index 8248dc1..7f0ca7e 100644
--- a/src/routes/notes.js
+++ b/src/routes/notes.js
@@ -1,8 +1,25 @@
 import { createNote, deleteNote, getNote, listNotes, updateNote } from '../services/notes.js';
 import { noteSummary } from '../utils/format.js';
 
+const DEFAULT_PAGE_SIZE = 5;
+const MAX_PAGE_SIZE = 50;
+
+// Parses a positive integer query param, falling back when missing or invalid.
+function positiveInt(value, fallback) {
+  const n = Number.parseInt(value, 10);
+  return Number.isFinite(n) && n >= 1 ? n : fallback;
+}
+
+function listPage(req) {
+  const page = positiveInt(req.query?.page, 1);
+  const pageSize = Math.min(positiveInt(req.query?.pageSize, DEFAULT_PAGE_SIZE), MAX_PAGE_SIZE);
+  const all = listNotes(req.user.id);
+  const items = all.slice((page - 1) * pageSize, page * pageSize).map(noteSummary);
+  return { status: 200, body: { items, page, pageSize, total: all.length } };
+}
+
 export const notesRoutes = {
-  'GET /notes': (req) => ({ status: 200, body: listNotes(req.user.id).map(noteSummary) }),
+  'GET /notes': listPage,
   'GET /notes/:id': (req) => {
     const note = getNote(req.user.id, req.params.id);
     return note ? { status: 200, body: note } : { status: 404, body: { error: 'not found' } };
diff --git a/src/utils/format.js b/src/utils/format.js
index 24a3a09..4c90f41 100644
--- a/src/utils/format.js
+++ b/src/utils/format.js
@@ -3,7 +3,7 @@
 // Dates are shown as YYYY-MM-DD in UTC.
 export function formatDate(ms) {
   const d = new Date(ms);
-  const month = String(d.getUTCMonth()).padStart(2, '0');
+  const month = String(d.getUTCMonth() + 1).padStart(2, '0');
   const day = String(d.getUTCDate()).padStart(2, '0');
   return `${d.getUTCFullYear()}-${month}-${day}`;
 }
diff --git a/tests/api.test.js b/tests/api.test.js
index 32d499e..964b47b 100644
--- a/tests/api.test.js
+++ b/tests/api.test.js
@@ -15,11 +15,35 @@ test('notes need a valid token', () => {
   assert.equal(handle({ method: 'GET', path: '/notes', headers: {} }).status, 401);
 });
 
-test('lists only my notes, newest first', () => {
+test('lists only my notes, newest first, paginated', () => {
   const res = as('u1', { method: 'GET', path: '/notes' });
   assert.equal(res.status, 200);
-  assert.equal(res.body.length, 8);
-  assert.equal(res.body[0].title, 'Car service');
+  assert.equal(res.body.total, 8);
+  assert.equal(res.body.page, 1);
+  assert.equal(res.body.pageSize, 5);
+  assert.equal(res.body.items.length, 5);
+  assert.equal(res.body.items[0].title, 'Car service');
+});
+
+test('pagination returns later pages and the remainder', () => {
+  const first = as('u1', { method: 'GET', path: '/notes', query: { page: '1', pageSize: '5' } });
+  const second = as('u1', { method: 'GET', path: '/notes', query: { page: '2', pageSize: '5' } });
+  assert.equal(second.body.items.length, 3);
+  assert.equal(second.body.page, 2);
+  const ids = [...first.body.items, ...second.body.items].map((n) => n.id);
+  assert.equal(new Set(ids).size, 8);
+  const beyond = as('u1', { method: 'GET', path: '/notes', query: { page: '3' } });
+  assert.deepEqual(beyond.body.items, []);
+  assert.equal(beyond.body.total, 8);
+});
+
+test('pageSize is capped at 50 and invalid values use defaults', () => {
+  const big = as('u1', { method: 'GET', path: '/notes', query: { pageSize: '500' } });
+  assert.equal(big.body.pageSize, 50);
+  assert.equal(big.body.items.length, 8);
+  const bad = as('u1', { method: 'GET', path: '/notes', query: { page: '0', pageSize: 'abc' } });
+  assert.equal(bad.body.page, 1);
+  assert.equal(bad.body.pageSize, 5);
 });
 
 test('creates and deletes a note', () => {
diff --git a/tests/format.test.js b/tests/format.test.js
new file mode 100644
index 0000000..7d69cc2
--- /dev/null
+++ b/tests/format.test.js
@@ -0,0 +1,14 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { formatDate, noteSummary } from '../src/utils/format.js';
+
+test('formatDate uses 1-based months', () => {
+  assert.equal(formatDate(Date.UTC(2026, 2, 15)), '2026-03-15');
+  assert.equal(formatDate(Date.UTC(2026, 0, 1)), '2026-01-01');
+  assert.equal(formatDate(Date.UTC(2026, 11, 31)), '2026-12-31');
+});
+
+test('noteSummary shows the correct created month', () => {
+  const note = { id: 1, title: 't', body: 'b', tags: [], createdAt: Date.UTC(2026, 2, 15) };
+  assert.equal(noteSummary(note).created, '2026-03-15');
+});
diff --git a/tests/rateLimit.test.js b/tests/rateLimit.test.js
new file mode 100644
index 0000000..3b72554
--- /dev/null
+++ b/tests/rateLimit.test.js
@@ -0,0 +1,50 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { createRateLimiter } from '../src/middleware/rateLimit.js';
+
+function setup(limit = 2, windowMs = 1000) {
+  const clock = { t: 0 };
+  const allow = createRateLimiter({ limit, windowMs, now: () => clock.t });
+  return { clock, allow };
+}
+
+test('allows up to limit calls per key, then blocks', () => {
+  const { allow } = setup(2);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+  assert.equal(allow('a'), false);
+});
+
+test('keys are counted independently', () => {
+  const { allow } = setup(1);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('b'), true);
+  assert.equal(allow('a'), false);
+  assert.equal(allow('b'), false);
+});
+
+test('window resets at the next multiple of windowMs', () => {
+  const { clock, allow } = setup(1, 1000);
+  clock.t = 999;
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+  clock.t = 1000;
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+});
+
+test('calls stay in the same window until the boundary', () => {
+  const { clock, allow } = setup(1, 1000);
+  clock.t = 1000;
+  assert.equal(allow('a'), true);
+  clock.t = 1999;
+  assert.equal(allow('a'), false);
+  clock.t = 2000;
+  assert.equal(allow('a'), true);
+});
+
+test('uses Date.now by default', () => {
+  const allow = createRateLimiter({ limit: 1, windowMs: 60 * 60 * 1000 });
+  assert.equal(typeof allow('a'), 'boolean');
+});