diff --git a/workers/updater/Scheduler.spec.mjs b/workers/updater/Scheduler.spec.mjs
index cf47289..c5ff7a7 100644
--- a/workers/updater/Scheduler.spec.mjs
+++ b/workers/updater/Scheduler.spec.mjs
@@ -392,3 +392,42 @@ describe('Worker routing', () => {
     expect((await worker.fetch(request(headers), fakeEnv, createExecutionContext())).status).toBe(200);
   });
 });
+
+it('keeps manual runs available with scheduling off and does not replay missed hours', async () => {
+  network();
+
+  let scheduler = stub();
+  await scheduler.ensureArmed();
+  await scheduler.setAutomaticScheduling(false);
+
+  expect(await scheduler.ensureArmed()).toEqual({ armed: false, automaticSchedulingEnabled: false });
+  expect(await scheduler.status()).toMatchObject({
+    automaticSchedulingEnabled: false,
+    alarmAt: null,
+    hourlyAt: null,
+    retryAt: null,
+  });
+
+  let manual = await scheduler.startManual('data');
+  expect(manual.ok).toBe(true);
+  expect(await scheduler.setAutomaticScheduling(true)).toMatchObject({ busy: true });
+
+  let status = await runAlarmUntil(scheduler, s => s.lastManualRun !== null);
+  expect(status.lastManualRun.ok).toBe(true);
+  expect(status.lastRun).toBeNull();
+  expect(status.alarmAt).toBeNull();
+  expect(status.automaticSchedulingEnabled).toBe(false);
+
+  // A stale platform alarm must not run automatic work after disabling it.
+  await runInDurableObject(scheduler, instance => instance.alarm());
+  expect((await scheduler.status()).lastRun).toBeNull();
+
+  expect((await scheduler.run({ only: ['Schedules'] })).ok).toBe(true);
+  expect((await scheduler.status()).alarmAt).toBeNull();
+
+  await scheduler.setAutomaticScheduling(true);
+  status = await scheduler.status();
+  expect(status.hourlyAt).toBe(nextRunAt());
+  expect(status.alarmAt).toBe(status.hourlyAt);
+  expect(status.lastRun).toBeNull();
+});
diff --git a/workers/updater/admin.spec.mjs b/workers/updater/admin.spec.mjs
index 6104ff9..2e2e334 100644
--- a/workers/updater/admin.spec.mjs
+++ b/workers/updater/admin.spec.mjs
@@ -63,3 +63,27 @@ it.each(['/', '/admin/'])(
     expect(await response.text()).not.toContain('__NONCE__');
   },
 );
+
+it('protects scheduling changes with Access, same-origin checks and boolean validation', async () => {
+  const request = (enabled, origin = url) => new Request(url + '/admin/api/scheduling', {
+    method: 'POST',
+    headers: { Origin: origin, 'Content-Type': 'application/json' },
+    body: JSON.stringify({ enabled }),
+  });
+  const setAutomaticScheduling = vi.fn(async enabled => ({ ok: true, automaticSchedulingEnabled: enabled }));
+  const scheduler = () => ({ setAutomaticScheduling });
+
+  verifyAccess.mockResolvedValue(null);
+  expect((await adminRequest(request(false), {}, scheduler)).status).toBe(401);
+
+  verifyAccess.mockResolvedValue({ email: 'admin@example.test' });
+  expect((await adminRequest(request(false, 'https://other.test'), {}, scheduler)).status).toBe(403);
+  expect((await adminRequest(request('false'), {}, scheduler)).status).toBe(400);
+  expect(setAutomaticScheduling).not.toHaveBeenCalled();
+
+  expect((await adminRequest(request(false), {}, scheduler)).status).toBe(200);
+  expect(setAutomaticScheduling).toHaveBeenCalledWith(false);
+
+  setAutomaticScheduling.mockResolvedValue({ ok: false, busy: true });
+  expect((await adminRequest(request(true), {}, scheduler)).status).toBe(409);
+});
diff --git a/workers/updater/preview/server.mjs b/workers/updater/preview/server.mjs
index 004d764..b49667f 100644
--- a/workers/updater/preview/server.mjs
+++ b/workers/updater/preview/server.mjs
@@ -9,6 +9,7 @@ const state = {
   preview: true,
   user: { email: 'Local preview' },
   paused: false,
+  automaticSchedulingEnabled: true,
   busy: false,
   hourlyAt: hour + 3600000 + 10000,
   retryAt: null,
@@ -68,7 +69,7 @@ createServer(async (request, response) => {
     if (request.method === 'GET' && url.pathname === '/admin/api/status')
       return json(state);
 
-    if (request.method === 'POST' && url.pathname === '/admin/api/run') {
+    if (request.method === 'POST' && ['/admin/api/run', '/admin/api/scheduling'].includes(url.pathname)) {
       if (request.headers.origin !== `http://${request.headers.host}`)
         return json({ error: 'Invalid origin.' }, 403);
 
@@ -84,7 +85,19 @@ createServer(async (request, response) => {
           return json({ error: 'Request too large.' }, 413);
       }
 
-      const { mode } = JSON.parse(body);
+      const input = JSON.parse(body);
+
+      if (url.pathname === '/admin/api/scheduling') {
+        if (typeof input?.enabled !== 'boolean')
+          return json({ error: 'Enabled must be a boolean.' }, 400);
+
+        state.automaticSchedulingEnabled = input.enabled;
+        state.hourlyAt = input.enabled ? Math.floor(Date.now() / 3600000) * 3600000 + 3610000 : null;
+
+        return json({ ok: true });
+      }
+
+      const { mode } = input;
 
       if (!['data', 'social', 'both'].includes(mode))
         return json({ error: 'Unknown mode.' }, 400);
diff --git a/workers/updater/src/Scheduler.mjs b/workers/updater/src/Scheduler.mjs
index 1c5b6cf..8bd5423 100644
--- a/workers/updater/src/Scheduler.mjs
+++ b/workers/updater/src/Scheduler.mjs
@@ -26,6 +26,8 @@ export class Scheduler extends DurableObject {
     // becomes one immediate full run, then the generic queue is retired.
     return {
       paused: saved.paused ?? false,
+      automaticSchedulingEnabled: saved.automaticSchedulingEnabled
+        ?? (this.env.AUTOMATIC_SCHEDULING_ENABLED !== 'false'),
       hourlyAt: saved.hourlyAt ?? null,
       retryAt: saved.retryAt ?? (saved.pending?.length ? Date.now() : null),
       retries: saved.retries ?? 0,
@@ -48,16 +50,70 @@ export class Scheduler extends DurableObject {
 
     let armed = (await this.ctx.storage.getAlarm()) === null;
 
-    state.hourlyAt ??= nextRunAt();
+    let manual = await this.#pendingManual();
+
+    if (!state.automaticSchedulingEnabled && !manual) {
+      await this.ctx.storage.deleteAlarm();
+
+      return { armed: false, automaticSchedulingEnabled: false };
+    }
+
+    if (state.automaticSchedulingEnabled)
+      state.hourlyAt ??= nextRunAt();
     await this.ctx.storage.put('state', state);
 
-    let alarmAt = (await this.#pendingManual()) ? Date.now() : (state.retryAt ?? state.hourlyAt);
+    let alarmAt = manual ? Date.now() : (state.retryAt ?? state.hourlyAt);
 
     await this.ctx.storage.setAlarm(alarmAt);
 
     return { armed, hourlyAt: state.hourlyAt, alarmAt };
   }
 
+  async setAutomaticScheduling(enabled) {
+    if (typeof enabled !== 'boolean')
+      return { ok: false, error: 'Enabled must be a boolean.' };
+
+    if (this.#running)
+      return { ok: false, busy: true, error: 'Wait for the current run to finish.' };
+
+    this.#running = true;
+
+    try {
+      if (await this.#pendingManual())
+        return { ok: false, busy: true, error: 'Wait for the queued run to finish.' };
+
+      let state = await this.#state();
+
+      if (state.paused)
+        return { ok: false, paused: true, error: 'The Worker is paused for maintenance.' };
+
+      if (state.automaticSchedulingEnabled !== enabled) {
+        state.hourlyAt = enabled ? nextRunAt() : null;
+        state.retryAt = null;
+        state.retries = 0;
+      }
+
+      state.automaticSchedulingEnabled = enabled;
+
+      if (enabled)
+        state.hourlyAt ??= nextRunAt();
+
+      await this.ctx.storage.transaction(async txn => {
+        await txn.put('state', state);
+
+        if (enabled) {
+          await txn.setAlarm(state.retryAt ?? state.hourlyAt);
+        } else {
+          await txn.deleteAlarm();
+        }
+      });
+
+      return { ok: true, automaticSchedulingEnabled: enabled };
+    } finally {
+      this.#running = false;
+    }
+  }
+
   async pause() {
     if (this.#running || (await this.#pendingManual()))
       return { ok: false, busy: true, error: 'Wait for the current run to finish before pausing.' };
@@ -254,6 +310,12 @@ export class Scheduler extends DurableObject {
         });
       }
 
+      if (!state.automaticSchedulingEnabled) {
+        await this.ctx.storage.deleteAlarm();
+
+        return;
+      }
+
       state.hourlyAt ??= nextRunAt();
 
       let scheduledFor = state.retryAt ?? state.hourlyAt;
diff --git a/workers/updater/src/admin/page.html b/workers/updater/src/admin/page.html
index db82e61..37ae787 100644
--- a/workers/updater/src/admin/page.html
+++ b/workers/updater/src/admin/page.html
@@ -445,7 +445,10 @@
           </div>
           <div class="sub" id="state-detail">Checking the updater</div>
         </div>
-        <div class="next"><small>Next scheduled run</small><strong id="next">—</strong></div>
+        <div class="next">
+          <small>Next scheduled run</small><strong id="next">—</strong>
+          <button class="refresh" id="scheduling" role="switch" aria-checked="false" disabled>Automatic scheduling</button>
+        </div>
       </section>
       <div class="section-label">
         <h2>Start a run</h2>
@@ -526,6 +529,8 @@
       }
 
       function updateControls() {
+        element('scheduling').disabled = sending || !state || state.busy || state.paused;
+
         for (const button of buttons)
           button.disabled = sending || !state || state.busy || state.paused;
       }
@@ -638,6 +643,10 @@
           element('state').textContent = 'Scheduler paused';
           element('dot').className = 'dot warning';
           element('state-detail').textContent = 'Manual runs are disabled while paused.';
+        } else if (!state.automaticSchedulingEnabled) {
+          element('state').textContent = 'Automatic scheduling off';
+          element('dot').className = 'dot neutral';
+          element('state-detail').textContent = 'Manual runs are available.';
         } else {
           element('state').textContent = 'Ready when you are';
           element('dot').className = 'dot';
@@ -650,7 +659,10 @@
           element('state-detail').textContent = `${name} · ${progress}`;
         }
 
-        element('next').textContent = state.paused ? 'Paused' : formatDate(state.retryAt || state.hourlyAt);
+        element('next').textContent = state.paused ? 'Paused'
+          : state.automaticSchedulingEnabled ? formatDate(state.retryAt || state.hourlyAt) : 'Off';
+        element('scheduling').setAttribute('aria-checked', String(state.automaticSchedulingEnabled));
+        element('scheduling').textContent = `Automatic scheduling: ${state.automaticSchedulingEnabled ? 'On' : 'Off'}`;
         element('live-run').hidden = !state.activeRun;
 
         if (state.activeRun) {
@@ -772,6 +784,29 @@
           }
         });
 
+      element('scheduling').addEventListener('click', async () => {
+        const enabled = !state.automaticSchedulingEnabled;
+        sending = true;
+        updateControls();
+
+        try {
+          await requestAdmin('scheduling', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ enabled }),
+          });
+          element('notice').textContent = enabled
+            ? 'Automatic scheduling enabled. The next run starts after the next hour.'
+            : 'Automatic scheduling disabled. You can still run updates manually.';
+        } catch (error) {
+          element('notice').textContent = error.message;
+        } finally {
+          sending = false;
+          await refreshStatus();
+          updateControls();
+        }
+      });
+
       element('refresh').addEventListener('click', refreshStatus);
       document.addEventListener('visibilitychange', () => {
         if (document.hidden)
diff --git a/workers/updater/src/admin/routes.mjs b/workers/updater/src/admin/routes.mjs
index 404d54c..c7c6064 100644
--- a/workers/updater/src/admin/routes.mjs
+++ b/workers/updater/src/admin/routes.mjs
@@ -29,7 +29,7 @@ export async function adminRequest(request, env, getScheduler) {
   if (request.method === 'GET' && url.pathname === '/admin/api/status')
     return json({ ...(await getScheduler().status()), user, preview: false });
 
-  if (request.method === 'POST' && url.pathname === '/admin/api/run') {
+  if (request.method === 'POST' && ['/admin/api/run', '/admin/api/scheduling'].includes(url.pathname)) {
     // Access cookies authenticate the user; require a same-origin JSON request as well.
     if (
       request.headers.get('Origin') !== url.origin ||
@@ -37,14 +37,25 @@ export async function adminRequest(request, env, getScheduler) {
     )
       return json({ error: 'A same-origin JSON request is required.' }, 403);
 
-    let mode;
+    let body;
 
     try {
-      ({ mode } = await request.json());
+      body = await request.json();
     } catch {
       return json({ error: 'Invalid request.' }, 400);
     }
 
+    if (url.pathname === '/admin/api/scheduling') {
+      if (typeof body?.enabled !== 'boolean')
+        return json({ error: 'Enabled must be a boolean.' }, 400);
+
+      let result = await getScheduler().setAutomaticScheduling(body.enabled);
+
+      return json(result, result.ok ? 200 : result.busy || result.paused ? 409 : 400);
+    }
+
+    let mode = body?.mode;
+
     if (!MANUAL_MODES.includes(mode))
       return json({ error: 'Unknown run mode.' }, 400);