Fixed world clock: no player time controls (ISS-117)

The world always runs at WORLD_TIME_SCALE = 24 (lib/worldClock.ts). A server
background tick (instrumentation.ts -> startBackgroundTick, 1 s interval)
advances the sim with no open browser; idle-pause freezes the clock exactly
while no plane is flying or in repair. Fresh worlds start year 2000
(STARTING_CLOCK_MS in seed.ts).

- Removed: POST /api/sim + OpenAPI entry, applyTimeControls/clampTimeScale,
  lib/timeScale.ts, LeftPane pause button + scale slider machinery,
  ISS-057 slow-on-landing/resume in flyPlane.
- Snapshot simState is now { clockMs } only; client extrapolates at the fixed
  rate between polls and freezes while idle (useSimClock).
- New test-only hook POST /api/test/set-timescale behind FLIGHT_TEST_HOOKS=1
  (sibling of set-health); all e2e setScale helpers call it, afterEach restores
  the world rate. E2E pause tests replaced by idle-pause assertions; sim.spec.ts
  activates the world via set-health + /repair for advance/expiry tests.

lib/db/client.test.ts

@@ -3,6 +3,8 @@ import os from 'node:os';
 import path from 'node:path';
 import initSqlJs from 'sql.js';
 import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { WORLD_TIME_SCALE } from '@/lib/worldClock';
+import { STARTING_CLOCK_MS } from '@/lib/game/seed';
 import { openGameDb, persist } from './client';
 import * as schema from './schema';
 
@@ -111,8 +113,9 @@ describe('openGameDb', () => {
     const account = (await inst.db.select().from(schema.account))[0];
     expect(account?.cash).toBeGreaterThan(0);
     const sim = (await inst.db.select().from(schema.simState))[0];
-    expect(sim?.paused).toBe(false);
-    expect(sim?.timeScale).toBe(1);
+    // ISS-117: fresh worlds start at the year-2000 game clock with the fixed world rate.
+    expect(sim?.clockMs).toBe(STARTING_CLOCK_MS);
+    expect(sim?.timeScale).toBe(WORLD_TIME_SCALE);
 
     // The seed was durably written: the file exists and is non-empty.
     const st = await fs.stat(file);

lib/deriveEvents.test.ts

@@ -47,7 +47,7 @@ const basePackage = (id: string): PackageState => ({
 
 const snapshot = (over: Partial<StateSnapshot> = {}): StateSnapshot => ({
   account: { cash: 20_000, reputation: 10 },
-  simState: { clockMs: 0, timeScale: 1, paused: false },
+  simState: { clockMs: 0 },
   planes: [basePlane('plane-starter')],
   packages: [],
   catalog: CATALOG,
@@ -59,7 +59,7 @@ const snapshot = (over: Partial<StateSnapshot> = {}): StateSnapshot => ({
 describe('diffSnapshots', () => {
   it('returns [] for identical snapshots (only clock/cash drift)', () => {
     const prev = snapshot();
-    const next = snapshot({ account: { cash: 21_000, reputation: 11 }, simState: { clockMs: 60_000, timeScale: 1, paused: false } });
+    const next = snapshot({ account: { cash: 21_000, reputation: 11 }, simState: { clockMs: 60_000 } });
     expect(diffSnapshots(prev, next)).toEqual([]);
   });
 

lib/game/actions.test.ts

@@ -21,7 +21,7 @@ import {
   repRate,
   SELL_FRACTION,
 } from './catalog';
-import { HUB_ICAO } from './seed';
+import { HUB_ICAO, STARTING_CLOCK_MS } from './seed';
 import {
   abandonPackage,
   buyPlane,
@@ -173,7 +173,7 @@ describe('flyPlane', () => {
     const plane = (await inst.db.select().from(schema.planes))[0];
     expect(plane.status).toBe('flying');
     expect(plane.destIcao).toBe('LEMD');
-    expect(plane.departureSimTime).toBe(T0); // seeded clock, no tick in direct calls
+    expect(plane.departureSimTime).toBe(STARTING_CLOCK_MS); // seeded game clock (ISS-117), no tick in direct calls
     const fc = await loadAirportsGeoJson();
     const origin = fc.features.find((f) => f.properties.icao === HUB_ICAO)!.properties;
     expect(plane.lat).toBe(origin.lat);
@@ -182,34 +182,6 @@ describe('flyPlane', () => {
     expect(plane.fuel).toBe(PLANE_TYPES.atr72.maxFuel);
   });
 
-  it('resumes a manual pause and restores lastSelectedTimeScale when the last grounded plane takes off (ISS-057)', async () => {
-    const inst = await freshDb('fly-resume.db');
-    // A landing slowed the sim to 1×; the player's last manually selected speed was 250.
-    await inst.db.update(schema.simState).set({ paused: true, timeScale: 1, lastSelectedTimeScale: 250 });
-
-    await flyPlane(inst, 'plane-starter', 'LEMD'); // sole grounded plane → airborne
-
-    const sim = (await inst.db.select().from(schema.simState))[0];
-    expect(sim.paused).toBe(false); // dispatch still resumes a manual pause…
-    expect(sim.timeScale).toBe(250); // …and restores the last selected speed
-  });
-
-  it('keeps 1× when another plane is still grounded after dispatch (ISS-057)', async () => {
-    const inst = await freshDb('fly-stayslow.db');
-    await inst.db.update(schema.simState).set({ timeScale: 1, lastSelectedTimeScale: 250 });
-    // A second grounded plane — the starter taking off leaves it on the ground.
-    await inst.db.insert(schema.planes).values({
-      id: 'plane-extra', model: 'atr72', status: 'available', fuel: 100, maxFuel: PLANE_TYPES.atr72.maxFuel,
-      locationIcao: HUB_ICAO, destIcao: null, lat: 50, lon: 8, departureSimTime: null,
-    });
-
-    await flyPlane(inst, 'plane-starter', 'LEMD');
-
-    const sim = (await inst.db.select().from(schema.simState))[0];
-    expect(sim.paused).toBe(false);
-    expect(sim.timeScale).toBe(1); // another plane on ground → stays slowed
-  });
-
   it('rejects a flying plane with 409', async () => {
     const inst = await freshDb('fly-flying.db');
     await inst.db.update(schema.planes)
@@ -462,14 +434,14 @@ describe('cancelQueuedLeg (v0.25.0, ISS-043)', () => {
 });
 
 describe('abandonPackage', () => {
-  // A loaded package created at T0 with a 10h window; the seeded sim clock is T0.
+  // A loaded package created at the seeded game clock with a 10h window (ISS-117).
   const REWARD = 1_000;
   const WINDOW_MS = 10 * 3_600_000;
 
   async function setupLoaded(name: string, status: 'loaded' | 'expired' = 'loaded') {
     const inst = await freshDb(name);
     // Always insert OPEN and load it through the real action…
-    await insertOpenPackage(inst, 'p-ab', { reward: REWARD, createdSimTime: T0, deadlineSimTime: T0 + WINDOW_MS });
+    await insertOpenPackage(inst, 'p-ab', { reward: REWARD, createdSimTime: STARTING_CLOCK_MS, deadlineSimTime: STARTING_CLOCK_MS + WINDOW_MS });
     await loadPackage(inst, 'p-ab', 'plane-starter');
     // …then flip to expired in place (what the tick would do once the deadline passes).
     if (status === 'expired') {
@@ -494,7 +466,7 @@ describe('abandonPackage', () => {
 
   it('scales to exactly 37.5% at the midpoint of the window', async () => {
     const inst = await setupLoaded('ab-mid.db');
-    await inst.db.update(schema.simState).set({ clockMs: T0 + WINDOW_MS / 2 }); // runAction ticks first in prod
+    await inst.db.update(schema.simState).set({ clockMs: STARTING_CLOCK_MS + WINDOW_MS / 2 }); // runAction ticks first in prod
 
     const { penalty } = await abandonPackage(inst, 'p-ab');
 
@@ -503,8 +475,8 @@ describe('abandonPackage', () => {
 
   it('caps at exactly 60% at and past the deadline', async () => {
     for (const [name, clock] of [
-      ['ab-deadline.db', T0 + WINDOW_MS],
-      ['ab-pastdeadline.db', T0 + WINDOW_MS * 2], // clamped — a not-yet-ticked loaded package past its deadline
+      ['ab-deadline.db', STARTING_CLOCK_MS + WINDOW_MS],
+      ['ab-pastdeadline.db', STARTING_CLOCK_MS + WINDOW_MS * 2], // clamped — a not-yet-ticked loaded package past its deadline
     ] as const) {
       const inst = await setupLoaded(name);
       await inst.db.update(schema.simState).set({ clockMs: clock });
@@ -735,7 +707,7 @@ describe('repairPlane (v0.39.0, ISS-069; gradual since v0.45.0, ISS-089)', () =>
     const plane = (await inst.db.select().from(schema.planes))[0];
     expect(plane.status).toBe('repairing');
     expect(plane.health).toBe(42); // NOT restored yet — the engine's finishRepairs pass heals it gradually…
-    expect(plane.repairUntilSimTime).toBe(T0 + REPAIR_DURATION_MS); // …with the gate set from the seeded clock (no tick in direct calls)
+    expect(plane.repairUntilSimTime).toBe(STARTING_CLOCK_MS + REPAIR_DURATION_MS); // …with the gate set from the seeded game clock (ISS-117; no tick in direct calls)
     const account = (await inst.db.select().from(schema.account))[0];
     expect(account.cash).toBeCloseTo(cashBefore - REPAIR_COST, 6);
   });

lib/game/actions.ts

@@ -173,14 +173,6 @@ export async function flyPlane(inst: GameDb, planeId: string, destIcao: string):
   if (cost > 0) {
     await inst.db.update(schema.account).set({ cash: Math.round((account.cash - cost) * 100) / 100 });
   }
-  // ISS-057: dispatch still resumes a MANUALLY paused sim (pause is manual-only now — landings
-  // slow to 1× instead of pausing), and restores the last manually selected speed when this
-  // dispatch took the LAST grounded plane airborne. Runs inside runAction(), so tick + controls
-  // + dispatch are atomic under the sim lock.
-  const sets: Partial<Pick<schema.SimStateRow, 'paused' | 'timeScale'>> = { paused: false };
-  const remaining = await inst.db.select().from(schema.planes).where(eq(schema.planes.status, 'available'));
-  if (remaining.length === 0) sets.timeScale = sim.lastSelectedTimeScale;
-  await inst.db.update(schema.simState).set(sets);
   await persist(inst);
 }
 

lib/game/seed.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, it } from 'vitest';
+import { WORLD_TIME_SCALE } from '@/lib/worldClock';
 import { haversineKm } from '@/lib/geo';
 import { PLANE_TYPES, repRate, STARTER_MODEL } from './catalog';
 import { SPECIALS } from './specials';
@@ -18,6 +19,7 @@ import {
   REWARD_PER_KM,
   rewardFor,
   STARTING_CASH,
+  STARTING_CLOCK_MS,
   STARTING_REPUTATION,
   type Rng,
   type SeedAirport,
@@ -73,7 +75,7 @@ describe('buildSeed', () => {
       expect(c.originIcao).not.toBe(c.destIcao);
       expect(c.status).toBe('open');
       expect(c.planeId).toBeNull();
-      expect(c.createdSimTime).toBe(NOW);
+      expect(c.createdSimTime).toBe(STARTING_CLOCK_MS); // game-clock origin, not wall time (ISS-117)
     }
     expect(new Set(seed.packages.map((c) => c.id)).size).toBe(seed.packages.length);
   });
@@ -101,22 +103,23 @@ describe('buildSeed', () => {
     }
   });
 
-  it('sets deadlines inside the 6–72h game-time window after now (scaled by any special status)', () => {
+  it('sets deadlines inside the 6–72h game-time window after the game-clock origin (scaled by any special status)', () => {
     const seed = seedWith(42);
     for (const c of seed.packages) {
       // v0.37.0 (ISS-073): a special's deadlineScale tightens the drawn window (e.g. priority → 3–36h).
+      // ISS-117: the window is anchored at STARTING_CLOCK_MS, not wall time.
       const scale = c.special ? SPECIALS[c.special]?.deadlineScale ?? 1 : 1;
-      expect(c.deadlineSimTime).toBeGreaterThan(NOW + 6 * 3_600_000 * scale - 1);
-      expect(c.deadlineSimTime).toBeLessThanOrEqual(NOW + 72 * 3_600_000 * scale);
+      expect(c.deadlineSimTime).toBeGreaterThan(STARTING_CLOCK_MS + 6 * 3_600_000 * scale - 1);
+      expect(c.deadlineSimTime).toBeLessThanOrEqual(STARTING_CLOCK_MS + 72 * 3_600_000 * scale);
     }
   });
 
   it('seeds the starting account and sim state', () => {
     const seed = seedWith(42);
     expect(seed.account).toEqual({ cash: STARTING_CASH, reputation: STARTING_REPUTATION });
-    // lastRealTickMs starts at the seed moment so the first tick-on-read advances ~0;
-    // lastSelectedTimeScale mirrors the seeded speed (v0.30.0, ISS-057).
-    expect(seed.simState).toEqual({ clockMs: NOW, timeScale: 1, paused: false, lastRealTickMs: NOW, lastSelectedTimeScale: 1 });
+    // ISS-117 (v0.52.0): game clock starts at year 2000 with the fixed world rate; lastRealTickMs is
+    // the REAL seed moment so the first tick-on-read advances ~0. paused/lastSelectedTimeScale are legacy columns.
+    expect(seed.simState).toEqual({ clockMs: STARTING_CLOCK_MS, timeScale: WORLD_TIME_SCALE, paused: false, lastRealTickMs: NOW, lastSelectedTimeScale: WORLD_TIME_SCALE });
   });
 
   it('is fully deterministic for a fixed RNG and inputs', () => {
@@ -186,7 +189,8 @@ describe('generatePackage (shared seed/spawn builder)', () => {
     const count = PACKAGE_COUNT_MIN + Math.floor(rngA() * (PACKAGE_COUNT_MAX - PACKAGE_COUNT_MIN + 1));
     const expected: string[] = [];
     for (let i = 0; i < count; i++) {
-      expected.push(JSON.stringify(generatePackage({ id: `package-${i + 1}`, airports: AIRPORTS, rng: rngA, nowMs: NOW })));
+      // ISS-117: buildSeed anchors packages at the game-clock origin, not the wall-time input.
+      expected.push(JSON.stringify(generatePackage({ id: `package-${i + 1}`, airports: AIRPORTS, rng: rngA, nowMs: STARTING_CLOCK_MS })));
     }
     const seed = buildSeed({ airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW });
     expect(seed.packages.map((c) => JSON.stringify(c))).toEqual(expected);

lib/game/seed.ts

@@ -1,4 +1,5 @@
 import { haversineKm } from '@/lib/geo';
+import { WORLD_TIME_SCALE } from '@/lib/worldClock';
 import { PLANE_TYPES, repRate, STARTER_MODEL } from './catalog';
 import { pickSpecial, SPECIALS } from './specials';
 
@@ -75,6 +76,10 @@ export interface SeedData {
 export const STARTING_CASH = 20_000;
 export const STARTING_REPUTATION = 10;
 
+// ISS-117 (v0.52.0): fresh worlds start at the top of year 2000 — a fixed game-time origin so
+// every new save begins from the same moment. Existing saves keep their own clock (no migration).
+export const STARTING_CLOCK_MS = Date.UTC(2000, 0, 1);
+
 // The starter plane grounds at a large central-European hub. If the ICAO is
 // ever missing from the dataset we fall back to the first airport rather than
 // failing first run. (EDDF = Frankfurt; EDDM is Munich — don't mix them up.)
@@ -291,20 +296,21 @@ export function buildSeed(input: {
 
   const count = PACKAGE_COUNT_MIN + Math.floor(rng() * (PACKAGE_COUNT_MAX - PACKAGE_COUNT_MIN + 1));
   // Stable index-based ids for the seed set; runtime-generated entities must use
-  // random UUIDs to avoid colliding with these.
+  // random UUIDs to avoid colliding with these. Deadlines are drawn relative to the GAME clock
+  // origin (ISS-117), not the real wall time, so they stay meaningful at the fixed world rate.
   const packages: SeedPackage[] = [];
   for (let i = 0; i < count; i++) {
-    packages.push(generatePackage({ id: `package-${i + 1}`, airports, rng, nowMs }));
+    packages.push(generatePackage({ id: `package-${i + 1}`, airports, rng, nowMs: STARTING_CLOCK_MS }));
   }
 
   return {
     plane,
     packages,
     account: { cash: STARTING_CASH, reputation: STARTING_REPUTATION },
-    // lastRealTickMs starts at the seed moment so the first tick-on-read advances
-    // by ~0 instead of treating "time since install" as elapsed play time.
-    // lastSelectedTimeScale (v0.30.0, ISS-057) mirrors the seeded speed — nothing has been
-    // selected manually yet, so resume would restore 1× anyway.
-    simState: { clockMs: nowMs, timeScale: 1, paused: false, lastRealTickMs: nowMs, lastSelectedTimeScale: 1 },
+    // ISS-117 (v0.52.0): the game clock starts at year 2000 with the fixed world rate; lastRealTickMs
+    // is the REAL seed moment so the first tick advances by ~0 instead of treating "time since
+    // install" as elapsed play time. paused/lastSelectedTimeScale are legacy columns kept for schema
+    // stability — no game code reads them anymore.
+    simState: { clockMs: STARTING_CLOCK_MS, timeScale: WORLD_TIME_SCALE, paused: false, lastRealTickMs: nowMs, lastSelectedTimeScale: WORLD_TIME_SCALE },
   };
 }

lib/game/state.ts

@@ -73,7 +73,9 @@ export interface PackageState {
 
 export interface StateSnapshot {
   account: { cash: number; reputation: number };
-  simState: { clockMs: number; timeScale: number; paused: boolean };
+  // ISS-117 (v0.52.0): the world rate is a fixed constant (WORLD_TIME_SCALE), not per-save state —
+  // only the clock itself is reported here.
+  simState: { clockMs: number };
   planes: PlaneState[];
   packages: PackageState[];
   // Market reference data (v0.10.0) — static per build, sent with every snapshot so
@@ -135,7 +137,7 @@ export async function getStateSnapshot(): Promise<StateSnapshot> {
 
   return {
     account: { cash: accountRow.cash, reputation: accountRow.reputation },
-    simState: { clockMs: simRow.clockMs, timeScale: simRow.timeScale, paused: simRow.paused },
+    simState: { clockMs: simRow.clockMs },
     catalog: catalogEntries(),
     fuelPricePerL: FUEL_PRICE_PER_L,
     sellFraction: SELL_FRACTION,

lib/mapData.test.ts

@@ -13,7 +13,7 @@ const AIRPORTS = new Map<string, AirportCoord>([
 function snapshot(overrides: Partial<StateSnapshot> = {}): StateSnapshot {
   return {
     account: { cash: 0, reputation: 0 },
-    simState: { clockMs: 0, timeScale: 1, paused: false },
+    simState: { clockMs: 0 },
     planes: [],
     packages: [],
     catalog: [

lib/openapi.test.ts

@@ -3,7 +3,7 @@ import { describe, expect, it } from 'vitest';
 import { openApiSpec } from './openapi';
 
 describe('OpenAPI spec', () => {
-  it('documents exactly the thirteen public endpoints (4 read + 9 player actions)', () => {
+  it('documents exactly the twelve public endpoints (3 read + 9 player actions)', () => {
     expect(Object.keys(openApiSpec.paths).sort()).toEqual([
       '/api/airports',
       '/api/market/buy-plane',
@@ -15,7 +15,6 @@ describe('OpenAPI spec', () => {
       '/api/planes/{planeId}/queue', // v0.25.0 (ISS-043)
       '/api/planes/{planeId}/queue/cancel', // v0.25.0 (ISS-043)
       '/api/planes/{planeId}/repair', // v0.39.0 (ISS-069)
-      '/api/sim',
       '/api/state',
       '/api/version',
     ]);
@@ -147,36 +146,14 @@ describe('OpenAPI spec', () => {
       'weightKg', // v0.27.0 (ISS-045) — package weight in kg
     ]);
 
+    // ISS-117 (v0.52.0): the snapshot carries only the game clock — time controls are gone.
     const sim = openApiSpec.components.schemas.SimState.properties;
-    expect(Object.keys(sim).sort()).toEqual(['clockMs', 'paused', 'timeScale']);
+    expect(Object.keys(sim).sort()).toEqual(['clockMs']);
 
     const packageStatus = openApiSpec.components.schemas.PackageState.properties.status;
     expect(packageStatus.enum.sort()).toEqual(['abandoned', 'delivered', 'expired', 'ignored', 'loaded', 'open']); // v0.29.0 (ISS-047 part B)
   });
 
-  it('describes POST /api/sim as SimControlsRequest → SimState with a 400 error shape', () => {
-    const post = openApiSpec.paths['/api/sim'].post;
-    expect(post.operationId).toBe('setSimControls');
-
-    const requestSchema = post.requestBody.content['application/json'].schema;
-    expect(requestSchema.$ref).toBe('#/components/schemas/SimControlsRequest');
-
-    const ok = post.responses[200].content['application/json'].schema;
-    expect(ok.$ref).toBe('#/components/schemas/SimState');
-    const bad = post.responses[400].content['application/json'].schema;
-    expect(bad.$ref).toBe('#/components/schemas/Error');
-
-    const controls = openApiSpec.components.schemas.SimControlsRequest.properties;
-    expect(Object.keys(controls).sort()).toEqual(['paused', 'timeScale']);
-    expect(controls.timeScale.type).toBe('number');
-    expect(controls.timeScale.minimum).toBe(1);
-    expect(controls.timeScale.maximum).toBe(1000);
-    expect(controls.paused.type).toBe('boolean');
-
-    const error = openApiSpec.components.schemas.Error.properties;
-    expect(Object.keys(error)).toEqual(['error']);
-  });
-
   it('documents the eight action endpoints: snapshot on 200, Error on their 4xx paths', () => {
     // The spec object is a literal type; these helpers view it as plain JSON.
     const post = (p: string) =>

lib/openapi.ts

@@ -37,7 +37,7 @@ export const openApiSpec = {
       get: {
         summary: 'Game state snapshot',
         description:
-          'Full current game state for client polling — account, sim clock, planes and packages, plus the static market reference data (catalog + economy constants) so clients can compute buy/sell previews locally. Tick-on-read: each call first advances the sim clock by (real time since last read) × timeScale (clamped per tick), so expiry/delivery/spawn are always applied before the snapshot is returned.',
+          'Full current game state for client polling — account, sim clock, planes and packages, plus the static market reference data (catalog + economy constants) so clients can compute buy/sell previews locally. The world clock advances on a ~1 s background tick at a fixed rate (v0.52.0, ISS-117: no player-facing time controls), clamped per tick; while no plane is flying or in repair the clock stays frozen. Each call ticks first, so expiry/delivery/spawn are always applied before the snapshot is returned.',
         operationId: 'getState',
         responses: {
           200: {
@@ -51,40 +51,6 @@ export const openApiSpec = {
         },
       },
     },
-    '/api/sim': {
-      post: {
-        summary: 'Set sim time controls',
-        description:
-          'Advance the sim clock (tick-on-read) and set the time scale / pause state. The clock is advanced first, so the returned simState already reflects current game time; package expiry, arrival delivery and market spawn run inside that tick.',
-        operationId: 'setSimControls',
-        requestBody: {
-          required: false,
-          content: {
-            'application/json': {
-              schema: { $ref: '#/components/schemas/SimControlsRequest' },
-            },
-          },
-        },
-        responses: {
-          200: {
-            description: 'Updated sim state',
-            content: {
-              'application/json': {
-                schema: { $ref: '#/components/schemas/SimState' },
-              },
-            },
-          },
-          400: {
-            description: 'Invalid body (not an object, unknown field, or wrong types)',
-            content: {
-              'application/json': {
-                schema: { $ref: '#/components/schemas/Error' },
-              },
-            },
-          },
-        },
-      },
-    },
     '/api/version': {
       get: {
         summary: 'App version',
@@ -493,24 +459,9 @@ export const openApiSpec = {
       SimState: {
         type: 'object',
         properties: {
-          clockMs: { type: 'integer', description: 'Sim-clock epoch ms (game time)' },
-          timeScale: { type: 'number', minimum: 1, maximum: 1000 },
-          paused: { type: 'boolean' },
-        },
-        required: ['clockMs', 'timeScale', 'paused'],
-      },
-      SimControlsRequest: {
-        type: 'object',
-        description: 'Partial update — omit a field to leave it unchanged.',
-        properties: {
-          timeScale: {
-            type: 'number',
-            minimum: 1,
-            maximum: 1000,
-            description: 'Game-time multiplier; values outside [1, 1000] are clamped. The UI offers the ladder 1/2/5/10/25/50/100/250/500/1000.',
-          },
-          paused: { type: 'boolean' },
+          clockMs: { type: 'integer', description: 'Sim-clock epoch ms (game time). The world runs at a fixed rate with no player-facing controls (v0.52.0, ISS-117).' },
         },
+        required: ['clockMs'],
       },
       LoadPackageRequest: {
         type: 'object',

lib/sim/engine.test.ts

@@ -10,26 +10,33 @@ import { haversineKm, initialBearingDeg } from '@/lib/geo';
 import { weatherFor } from '@/lib/weather';
 import { FUEL_DISCOUNT_PER_REP, FUEL_PRICE_PER_L, MAX_FUEL_DISCOUNT, PLANE_TYPES, REPAIR_DURATION_MS, repRate, WEAR_PER_KM } from '@/lib/game/catalog';
 import { SPECIALS } from '@/lib/game/specials';
-import { MARKET_TARGET_OPEN_PACKAGES, mulberry32 } from '@/lib/game/seed';
+import { MARKET_TARGET_OPEN_PACKAGES, mulberry32, STARTING_CLOCK_MS } from '@/lib/game/seed';
 import { arrivalTimeFor, fuelAtWeighted, requiredFuelFor, windBurnFactor } from './movement';
 import {
-  clampTimeScale,
   deliverPackages,
   expirePackages,
   finishRepairs,
   MAX_TICK_ELAPSED_MS,
-  MAX_TIME_SCALE,
-  MIN_TIME_SCALE,
   reputationGainFor,
+  shouldAdvanceTime,
   spawnCoveragePackages,
   spawnOpenPackages,
   tickOnce,
+  WORLD_TIME_SCALE,
 } from './engine';
 
 // Engine tests run against throwaway DB files (openGameDb) with fake timers so
 // Date.now() — the only wall-clock input to a tick — is fully controlled. The
-// public tickNow()/applyTimeControls() wrappers (singleton + lock) are covered
-// by app/api/sim/route.test.ts and the e2e suite.
+// public tickNow()/setTestTimeScale() wrappers (singleton + lock) are covered by the e2e suite
+// (every spec's setScale helper hits /api/test/set-timescale; sim.spec.ts pins its validation).
+
+// ISS-117: fresh DBs seed a GROUNDED starter, so any test that needs an advancing world must put
+// a plane in flight first — departureSimTime at the game-clock origin keeps its arrival hours away.
+async function makeWorldActive(inst: Awaited<ReturnType<typeof openGameDb>>) {
+  await inst.db.update(schema.planes)
+    .set({ status: 'flying', destIcao: 'LEMD', departureSimTime: STARTING_CLOCK_MS })
+    .where(eq(schema.planes.id, 'plane-starter'));
+}
 
 let dir: string;
 const T0 = 1_750_000_000_000; // seed moment / fake "now" at DB open
@@ -53,43 +60,46 @@ async function freshDb(name: string) {
 describe('tickOnce — clock advance', () => {
   it('advances the clock by elapsed real ms × timeScale', async () => {
     const inst = await freshDb('scale.db');
+    await makeWorldActive(inst); // a grounded fleet would freeze the world (ISS-117)
     vi.setSystemTime(T0 + 1_000); // one real second later
     await inst.db.update(schema.simState).set({ timeScale: 5 });
 
     const sim = await tickOnce(inst);
 
-    expect(sim.clockMs).toBe(T0 + 5_000); // 1 s × 5
+    expect(sim.clockMs).toBe(STARTING_CLOCK_MS + 5_000); // 1 s × 5
     expect(sim.lastRealTickMs).toBe(T0 + 1_000);
   });
 
-  it('freezes the clock while paused but keeps tracking real time', async () => {
-    const inst = await freshDb('pause.db');
-    await inst.db.update(schema.simState).set({ paused: true, timeScale: 60 });
+  it('freezes the clock while the fleet is fully grounded but keeps tracking real time', async () => {
+    const inst = await freshDb('idle.db'); // seeded starter is on the ground → idle (ISS-117)
 
-    vi.setSystemTime(T0 + 3_600_000); // an hour of real pause
+    vi.setSystemTime(T0 + 3_600_000); // an hour of real idleness
     let sim = await tickOnce(inst);
-    expect(sim.clockMs).toBe(T0); // frozen — no advance at all
+    expect(sim.clockMs).toBe(STARTING_CLOCK_MS); // frozen — no advance at all
     expect(sim.lastRealTickMs).toBe(T0 + 3_600_000);
 
-    // Unpause: resumes from where it stopped, with NO catch-up for the pause.
-    await inst.db.update(schema.simState).set({ paused: false });
+    // A plane takes off: resumes from where it stopped, with NO catch-up for the idle time.
+    await inst.db.update(schema.simState).set({ timeScale: 60 });
+    await makeWorldActive(inst);
     vi.setSystemTime(T0 + 3_600_500);
     sim = await tickOnce(inst);
-    expect(sim.clockMs).toBe(T0 + 500 * 60); // only the 500 ms since unpausing × 60
+    expect(sim.clockMs).toBe(STARTING_CLOCK_MS + 500 * 60); // only the 500 ms since activity × 60
   });
 
   it('clamps long absences: a 1-hour gap advances at most MAX_TICK_ELAPSED_MS × scale', async () => {
     const inst = await freshDb('clamp.db');
+    await makeWorldActive(inst);
     vi.setSystemTime(T0 + 3_600_000); // server sat idle for an hour
 
-    const sim = await tickOnce(inst); // timeScale is the seeded 1
+    const sim = await tickOnce(inst); // timeScale is the seeded WORLD_TIME_SCALE
 
-    expect(sim.clockMs).toBe(T0 + MAX_TICK_ELAPSED_MS); // exactly one clamped tick, not a fast-forward
+    expect(sim.clockMs).toBe(STARTING_CLOCK_MS + MAX_TICK_ELAPSED_MS * WORLD_TIME_SCALE); // exactly one clamped tick, not a fast-forward
     vi.setSystemTime(T0); // reset for later tests in this file
   });
 
   it('does not advance when two ticks land in the same millisecond', async () => {
     const inst = await freshDb('same-ms.db');
+    await makeWorldActive(inst);
     vi.setSystemTime(T0 + 1_000);
     const a = await tickOnce(inst);
     const b = await tickOnce(inst); // no real time passed since `a`
@@ -100,15 +110,17 @@ describe('tickOnce — clock advance', () => {
 describe('expirePackages', () => {
   it('flips open AND loaded packages past their deadline; terminal statuses never expire', async () => {
     const inst = await freshDb('expiry.db');
-    const clock = T0 + 100_000;
+    // Game-clock anchor just after the seed moment — well inside every seeded package's deadline
+    // window (DEADLINE_MIN_HOURS), so only the rows inserted below can expire.
+    const clock = STARTING_CLOCK_MS + 100_000;
 
     await inst.db.insert(schema.packages).values([
-      { id: 'p-open-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'open', planeId: null, createdSimTime: T0 },
-      { id: 'p-open-future', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock + 1, status: 'open', planeId: null, createdSimTime: T0 },
-      { id: 'p-loaded-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
-      { id: 'p-delivered-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'delivered', planeId: null, createdSimTime: T0 },
-      { id: 'p-abandoned-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'abandoned', planeId: null, createdSimTime: T0 },
-      { id: 'p-ignored-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'ignored', planeId: null, createdSimTime: T0 },
+      { id: 'p-open-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'open', planeId: null, createdSimTime: STARTING_CLOCK_MS },
+      { id: 'p-open-future', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock + 1, status: 'open', planeId: null, createdSimTime: STARTING_CLOCK_MS },
+      { id: 'p-loaded-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'loaded', planeId: 'plane-starter', createdSimTime: STARTING_CLOCK_MS },
+      { id: 'p-delivered-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'delivered', planeId: null, createdSimTime: STARTING_CLOCK_MS },
+      { id: 'p-abandoned-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'abandoned', planeId: null, createdSimTime: STARTING_CLOCK_MS },
+      { id: 'p-ignored-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'ignored', planeId: null, createdSimTime: STARTING_CLOCK_MS },
     ]);
 
     const n = await expirePackages(inst, clock);
@@ -127,9 +139,9 @@ describe('expirePackages', () => {
     const inst = await freshDb('expiry-edge.db');
     await inst.db.insert(schema.packages).values({
       id: 'p-edge', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1,
-      deadlineSimTime: T0 + 50_000, status: 'open', planeId: null, createdSimTime: T0,
+      deadlineSimTime: STARTING_CLOCK_MS + 50_000, status: 'open', planeId: null, createdSimTime: STARTING_CLOCK_MS,
     });
-    expect(await expirePackages(inst, T0 + 50_000)).toBe(1); // <= is inclusive
+    expect(await expirePackages(inst, STARTING_CLOCK_MS + 50_000)).toBe(1); // <= is inclusive
   });
 });
 
@@ -516,11 +528,13 @@ describe('finishRepairs (v0.39.0, ISS-069)', () => {
 
   it('runs inside tickOnce even when nothing landed: a past gate flips the plane back', async () => {
     const inst = await freshDb('repair-tick.db');
+    // The repairing plane keeps the world advancing (ISS-117); scale pinned to 1 for clean math.
+    await inst.db.update(schema.simState).set({ timeScale: 1 });
     await inst.db.update(schema.planes)
-      .set({ status: 'repairing', repairUntilSimTime: T0 + 1_500 })
+      .set({ status: 'repairing', repairUntilSimTime: STARTING_CLOCK_MS + 1_500 })
       .where(eq(schema.planes.id, 'plane-starter'));
 
-    vi.setSystemTime(T0 + 2_000); // one clamped tick at scale 1 → clock T0+2000 ≥ gate; nothing is flying
+    vi.setSystemTime(T0 + 2_000); // one clamped tick at scale 1 → clock STARTING_CLOCK_MS+2000 ≥ gate
     await tickOnce(inst);
 
     const plane = (await inst.db.select().from(schema.planes))[0];
@@ -560,101 +574,35 @@ describe('finishRepairs (v0.39.0, ISS-069)', () => {
   });
 });
 
-describe('slow to 1× when a landing leaves any plane on the ground (ISS-057)', () => {
-  const FROM = 'EDDF';
-  const TO = 'LEMD';
+describe('idle-pause — the world freezes when nothing is happening (ISS-117)', () => {
+  it('shouldAdvanceTime: grounded/empty fleets are idle; any flying or repairing plane advances', () => {
+    expect(shouldAdvanceTime([])).toEqual({ advance: false, flying: 0, repairing: 0 });
+    expect(shouldAdvanceTime([{ status: 'available' }, { status: 'available' }])).toEqual({ advance: false, flying: 0, repairing: 0 });
+    expect(shouldAdvanceTime([{ status: 'flying' }, { status: 'available' }])).toEqual({ advance: true, flying: 1, repairing: 0 });
+    expect(shouldAdvanceTime([{ status: 'repairing' }])).toEqual({ advance: true, flying: 0, repairing: 1 });
+    expect(shouldAdvanceTime([{ status: 'flying' }, { status: 'repairing' }])).toEqual({ advance: true, flying: 1, repairing: 1 });
+  });
 
-  // Starter flying EDDF→LEMD with departureSimTime set so its arrival is EXACTLY T0 —
-  // any advancing tick past T0 finalizes it. timeScale is the value under test;
-  // lastSelectedTimeScale mirrors what a manual POST /api/sim would have stored.
-  async function setupLanding(name: string, timeScale: number) {
-    const inst = await freshDb(name);
-    const fc = await loadAirportsGeoJson();
-    const from = fc.features.find((f) => f.properties.icao === FROM)!.properties;
-    const to = fc.features.find((f) => f.properties.icao === TO)!.properties;
-    const km = haversineKm(from.lat, from.lon, to.lat, to.lon);
-    const type = PLANE_TYPES.atr72;
+  it('a fully grounded fleet freezes the clock but keeps tracking real time', async () => {
+    const inst = await freshDb('idle-pause.db'); // seeded starter is on the ground → idle
+    vi.setSystemTime(T0 + 3_600_000);
 
-    await inst.db.update(schema.simState).set({ timeScale, lastSelectedTimeScale: timeScale });
+    const sim = await tickOnce(inst);
+
+    expect(sim.clockMs).toBe(STARTING_CLOCK_MS); // frozen — no advance at all
+    expect(sim.lastRealTickMs).toBe(T0 + 3_600_000); // …but the real-time anchor moved on
+  });
+
+  it('a repairing plane keeps the world advancing', async () => {
+    const inst = await freshDb('idle-repair.db');
     await inst.db.update(schema.planes)
-      .set({ status: 'flying', destIcao: TO, departureSimTime: T0 - travelMs(km, type.speedKmh), fuel: type.maxFuel })
+      .set({ status: 'repairing', repairUntilSimTime: STARTING_CLOCK_MS + REPAIR_DURATION_MS })
       .where(eq(schema.planes.id, 'plane-starter'));
 
-    return { inst, from, km, type };
-  }
-
-  it('last plane lands → sim slows to 1× WITHOUT pausing; lastSelectedTimeScale is preserved', async () => {
-    const { inst } = await setupLanding('slow-last.db', 1000);
-    vi.setSystemTime(T0 + 2_000); // one full clamped tick at scale 1000 → clock T0+2e6 ≥ arrival (T0)
-
+    vi.setSystemTime(T0 + 1_000);
     const sim = await tickOnce(inst);
 
-    expect(sim.paused).toBe(false); // no pause anymore — ISS-057 replaces it with a slow-down…
-    expect((await inst.db.select().from(schema.simState))[0].paused).toBe(false); // …persisted on the row…
-    expect(sim.timeScale).toBe(1); // …slowed to the floor…
-    expect(sim.lastSelectedTimeScale).toBe(1000); // …with the last manual speed kept for resume
-    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available'); // landing itself unchanged
-  });
-
-  it('a landing while another plane is still flying → slows to 1× (any plane on ground)', async () => {
-    const { inst, from, type } = await setupLanding('slow-other.db', 1000);
-    // A second plane on the same route departing at T0 — arrives far after this tick's clock.
-    await inst.db.insert(schema.planes).values({
-      id: 'p-b', model: 'atr72', status: 'flying', fuel: type.maxFuel, maxFuel: type.maxFuel,
-      locationIcao: FROM, destIcao: TO, lat: from.lat, lon: from.lon, departureSimTime: T0,
-    });
-
-    vi.setSystemTime(T0 + 2_000);
-    const sim = await tickOnce(inst);
-
-    expect(sim.paused).toBe(false);
-    expect(sim.timeScale).toBe(1); // the just-landed starter is on ground → slow (literal issue reading)
-    const byId = new Map((await inst.db.select().from(schema.planes)).map((p) => [p.id, p.status]));
-    expect(byId.get('plane-starter')).toBe('available'); // the starter did land…
-    expect(byId.get('p-b')).toBe('flying'); // …but the fleet is not idle — still slowed
-  });
-
-  it('already at 1× → stays 1 (no-op slow)', async () => {
-    const { inst } = await setupLanding('slow-one.db', 1);
-    vi.setSystemTime(T0 + 2_000); // one tick at scale 1 advances 2e3 game ms — past the T0 arrival
-
-    const sim = await tickOnce(inst);
-
-    expect(sim.paused).toBe(false);
-    expect(sim.timeScale).toBe(1);
-    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
-  });
-
-  it('a chained plane does NOT slow the sim (nothing is grounded)', async () => {
-    const { inst } = await setupLanding('slow-chain.db', 1000); // full tank, arrival exactly T0
-    // A queued next hop with plenty of fuel → chains on landing instead of grounding.
-    await inst.db.update(schema.planes)
-      .set({ queue: JSON.stringify(['EDDV']) })
-      .where(eq(schema.planes.id, 'plane-starter'));
-
-    vi.setSystemTime(T0 + 2_000); // one full clamped tick at scale 1000 → clock T0+2e6 ≥ arrival (T0)
-    const sim = await tickOnce(inst);
-
-    expect(sim.paused).toBe(false);
-    expect(sim.timeScale).toBe(1000); // still flying after the chain, nothing grounded — no slow…
-    const plane = (await inst.db.select().from(schema.planes))[0];
-    expect(plane.status).toBe('flying'); // …the fresh select in tickOnce counts it as airborne
-    expect(plane.destIcao).toBe('EDDV');
-  });
-
-  it('manually-paused sim is untouched by ticks (no landing processed while paused)', async () => {
-    const inst = await freshDb('slow-paused.db');
-    // The fleet is fully grounded (the seeded starter) — a paused tick must not touch the
-    // controls even though "any plane on ground" holds: the trigger requires a landing this tick.
-    await inst.db.update(schema.simState).set({ timeScale: 1000, lastSelectedTimeScale: 1000, paused: true });
-
-    vi.setSystemTime(T0 + 5_000);
-    const sim = await tickOnce(inst);
-
-    expect(sim.paused).toBe(true); // no landing processed while paused → trigger never fires
-    expect(sim.timeScale).toBe(1000);
-    expect(sim.lastSelectedTimeScale).toBe(1000);
-    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
+    expect(sim.clockMs).toBeGreaterThan(STARTING_CLOCK_MS); // the repair gate is what keeps time moving
   });
 });
 
@@ -789,7 +737,13 @@ describe('spawnCoveragePackages (v0.8.0 spawn coverage rule)', () => {
 
   it('runs inside tickOnce: a fresh DB gains an EDDF-origin package after one advancing tick', async () => {
     const inst = await freshDb('coverage-tick.db');
-    vi.setSystemTime(T0 + 1_000); // one real second → advanceMs > 0 at scale 1
+    // A second, airborne plane keeps the world advancing (ISS-117) while the seeded starter stays
+    // grounded — which is what coverage spawns for. Arrival is hours out, so it never lands here.
+    await inst.db.insert(schema.planes).values({
+      id: 'p-air', model: 'atr72', status: 'flying', fuel: 6300, maxFuel: 6300,
+      locationIcao: 'EDDF', destIcao: 'LEMD', lat: 50.03, lon: 8.57, departureSimTime: STARTING_CLOCK_MS,
+    });
+    vi.setSystemTime(T0 + 1_000); // one real second → advanceMs > 0 at the seeded scale
 
     await tickOnce(inst);
 
@@ -800,32 +754,6 @@ describe('spawnCoveragePackages (v0.8.0 spawn coverage rule)', () => {
   });
 });
 
-describe('clampTimeScale — v0.14.0 ladder bounds [1, 1000]', () => {
-  it('clamps below-minimum values to MIN_TIME_SCALE', () => {
-    expect(clampTimeScale(0)).toBe(MIN_TIME_SCALE);
-    expect(clampTimeScale(-5)).toBe(MIN_TIME_SCALE);
-    expect(clampTimeScale(0.1)).toBe(MIN_TIME_SCALE);
-  });
-
-  it('clamps above-maximum values to MAX_TIME_SCALE', () => {
-    expect(clampTimeScale(1001)).toBe(MAX_TIME_SCALE);
-    expect(clampTimeScale(2000)).toBe(MAX_TIME_SCALE);
-    expect(clampTimeScale(Number.MAX_SAFE_INTEGER)).toBe(MAX_TIME_SCALE);
-  });
-
-  it('passes in-range values through unclamped — ladder and off-ladder alike', () => {
-    for (const s of [1, 2, 5, 10, 25, 50, 100, 250, 500, 1000]) {
-      expect(clampTimeScale(s)).toBe(s); // the full v0.14.0 slider ladder
-    }
-    expect(clampTimeScale(37)).toBe(37); // off-ladder but in range (e.g. a legacy value)
-  });
-
-  it('keeps the endpoints exact', () => {
-    expect(clampTimeScale(MIN_TIME_SCALE)).toBe(MIN_TIME_SCALE);
-    expect(clampTimeScale(MAX_TIME_SCALE)).toBe(MAX_TIME_SCALE);
-  });
-});
-
 // Local helper mirroring lib/sim/movement.ts (kept private there on purpose — the
 // engine composes arrivalTimeFor; tests just need the duration for fixtures).
 function travelMs(km: number, speedKmh: number): number {

lib/sim/engine.ts

@@ -18,20 +18,20 @@ import {
 } from '@/lib/game/seed';
 import { arrivalTimeFor, fuelAtWeighted, requiredFuelFor, windBurnFactor } from './movement';
 
-// Server-authoritative sim engine (v0.7.0) — tick-on-read: there is NO background
-// timer. Every read/action endpoint calls tickNow() first; the clock advances by
-// (real ms since last tick) × timeScale, clamped per tick so long absences never
-// fast-forward the game.
+// Server-authoritative sim engine (v0.7.0). ISS-117 (v0.52.0): the clock advances on a background
+// tick (~1 s, started at boot from instrumentation.ts) AND on every read/action — both through the
+// same locked tickOnce path. Each tick advances by (real ms since last tick) × timeScale, clamped
+// per tick so long absences never fast-forward the game; while no plane is flying or in repair the
+// clock stays frozen (idle-pause) but lastRealTickMs keeps tracking real time.
 
-// Clamp constant: max real-time gap counted by a single tick. Chosen at 2000 ms —
-// comfortably above a normal client poll interval (~1 s), so active play advances
-// ~real time × scale; small enough that one stale read after an absence moves game
-// time by at most 2 s × scale (≈ 33 min even at max scale 1000). The sim therefore
-// only meaningfully progresses while actively polled.
+// Clamp constant: max real-time gap counted by a single tick. Chosen at 2000 ms — comfortably above
+// both the client poll interval (~1 s) and the background-tick interval, so active play advances
+// ~real time × scale; small enough that one stale read after an absence moves game time by at most
+// 2 s × scale.
 export const MAX_TICK_ELAPSED_MS = 2_000;
 
-export const MIN_TIME_SCALE = 1;
-export const MAX_TIME_SCALE = 1000; // top of the slider ladder (v0.14.0)
+// ISS-117: the fixed world rate — re-exported here so server code and tests have one familiar home.
+export { WORLD_TIME_SCALE } from '@/lib/worldClock';
 
 // Reputation gain per delivered package: BASE + PER_KM × great-circle km, rounded
 // to 2 decimals (reputation is REAL). A short hop (~300 km) earns ~1.15 rep, a
@@ -43,11 +43,6 @@ export function reputationGainFor(km: number): number {
   return Math.round((REP_BASE + REP_PER_KM * km) * 100) / 100;
 }
 
-export interface SimControlsInput {
-  timeScale?: number;
-  paused?: boolean;
-}
-
 // Serialize ticks across concurrent requests (Next.js route handlers run in the
 // same process): each tick re-reads sim_state after the previous one wrote it, so
 // no advance is ever applied twice.
@@ -63,23 +58,36 @@ function withLock<T>(fn: () => Promise<T>): Promise<T> {
 
 // --- Tick core (takes a GameDb so unit tests can inject their own instance) ---
 
+// ISS-117: idle-pause decision — pure, so unit tests feed it synthetic fleets. The world clock
+// advances only while something is happening: at least one plane flying OR in repair. A fully
+// grounded fleet freezes the clock (and with it expiries/spawns) until a dispatch or repair starts.
+export function shouldAdvanceTime(planes: Array<{ status: string }>): { advance: boolean; flying: number; repairing: number } {
+  let flying = 0;
+  let repairing = 0;
+  for (const p of planes) {
+    if (p.status === 'flying') flying++;
+    else if (p.status === 'repairing') repairing++;
+  }
+  return { advance: flying > 0 || repairing > 0, flying, repairing };
+}
+
 export async function tickOnce(inst: GameDb): Promise<schema.SimStateRow> {
   const rows = await inst.db.select().from(schema.simState);
   const sim = rows[0];
   if (!sim) throw new Error('sim_state row missing');
 
   const nowMs = Date.now();
+  // ISS-117: frozen while nothing is happening (see shouldAdvanceTime). lastRealTickMs still
+  // tracks real time, so a takeoff resumes cleanly with no catch-up jump for the idle duration.
+  const planeRows = await inst.db.select().from(schema.planes);
+  const { advance } = shouldAdvanceTime(planeRows.map((p) => ({ status: p.status })));
   const elapsed = Math.max(0, nowMs - sim.lastRealTickMs);
-  // While paused the clock is frozen; lastRealTickMs still tracks real time so
-  // unpausing resumes cleanly with no catch-up jump for the pause duration.
-  const advanceMs = sim.paused ? 0 : Math.min(elapsed, MAX_TICK_ELAPSED_MS) * sim.timeScale;
+  const advanceMs = advance ? Math.min(elapsed, MAX_TICK_ELAPSED_MS) * sim.timeScale : 0;
   const clockMs = Math.round(sim.clockMs + advanceMs);
 
-  let landedThisTick = 0;
   if (advanceMs > 0) {
     await expirePackages(inst, clockMs);
-    // ISS-057: remember the landings so the tick can slow down when a plane is left on ground.
-    landedThisTick = await deliverPackages(inst, clockMs);
+    await deliverPackages(inst, clockMs);
     // v0.39.0 (ISS-069): repairs whose gate has passed flip back to 'available' — runs even when
     // nothing landed this tick; BEFORE the spawns so a just-repaired plane gets coverage work too.
     await finishRepairs(inst, clockMs);
@@ -89,25 +97,8 @@ export async function tickOnce(inst: GameDb): Promise<schema.SimStateRow> {
     await spawnCoveragePackages(inst, clockMs);
   }
 
-  const sets: Partial<Pick<schema.SimStateRow, 'clockMs' | 'lastRealTickMs' | 'timeScale'>> = {
-    clockMs,
-    lastRealTickMs: nowMs,
-  };
-  // Slow on landing (ISS-057): when ≥1 plane landed this tick and ANY plane is grounded
-  // ('available') afterwards, drop the sim to MIN_TIME_SCALE — a just-landed plane counts, so
-  // any real landing slows. A chained plane stays 'flying' via deliverPackages' auto-chain
-  // branch, so a pure-chain tick with nothing grounded does NOT slow. Pause is manual-only now;
-  // flyPlane restores lastSelectedTimeScale when the last grounded plane takes off. Arrival-
-  // triggered by design: a grounded fleet at high scale is left alone (no idle-enforcement), and
-  // a paused tick never processes landings (advanceMs === 0), so the trigger only fires on an
-  // advancing tick — a manual speed change while planes sit grounded survives until the next landing.
-  if (landedThisTick > 0) {
-    const available = await inst.db.select().from(schema.planes).where(eq(schema.planes.status, 'available'));
-    if (available.length >= 1) sets.timeScale = MIN_TIME_SCALE;
-  }
-
   // Persist lastRealTickMs even when nothing advanced — it is the tick anchor.
-  await inst.db.update(schema.simState).set(sets);
+  await inst.db.update(schema.simState).set({ clockMs, lastRealTickMs: nowMs });
   await persist(inst);
   const updated = (await inst.db.select().from(schema.simState))[0];
   if (!updated) throw new Error('sim_state row missing after tick');
@@ -174,8 +165,7 @@ export async function finishRepairs(inst: GameDb, clockMs: number): Promise<numb
 // remaining fuel and the queue kept intact for a later dispatch.
 // Idempotent — a finalized plane either leaves the 'flying' state or starts a NEW
 // leg whose own arrival is in the future, so it can never be awarded twice.
-// Returns planes landed. NOTE: runs BEFORE tickOnce's slow-down check on purpose —
-// a chained plane is already 'flying' again here, so a pure-chain landing never slows the sim.
+// Returns planes landed.
 export async function deliverPackages(inst: GameDb, clockMs: number): Promise<number> {
   const [planeRows, packageRows] = await Promise.all([
     inst.db.select().from(schema.planes),
@@ -423,6 +413,17 @@ export function tickNow(): Promise<schema.SimStateRow> {
   return withLock(async () => tickOnce(await getGameDb()));
 }
 
+// ISS-117: the world clock runs even with nobody polling — a ~1 s interval drives the same locked
+// tick path as reads/actions. Started once at server boot from instrumentation.ts (Next ≥15); the
+// guard makes double-starts harmless (dev HMR reloads).
+let backgroundTimer: ReturnType<typeof setInterval> | null = null;
+export function startBackgroundTick(intervalMs = 1_000): void {
+  if (backgroundTimer !== null) return;
+  backgroundTimer = setInterval(() => {
+    tickNow().catch((err) => console.error('flight: background tick failed', err));
+  }, intervalMs);
+}
+
 // Run a game action atomically with respect to ticks (v0.8.0): the clock is
 // advanced FIRST so validation and mutation see current game time, then fn runs —
 // all under the same promise lock as tickNow(), so no concurrent request can
@@ -436,31 +437,17 @@ export function runAction<T>(fn: (inst: GameDb) => Promise<T>): Promise<T> {
   });
 }
 
-// Tick first so the returned state reflects current time, then apply the new
-// controls. timeScale is clamped to [1, 1000]; validation of raw input happens in
-// the route handler (400 on non-number / non-boolean). ISS-057: posting a timeScale
-// ALSO records it as lastSelectedTimeScale — the resume target flyPlane restores when
-// the last grounded plane takes off. A {paused}-only post never touches it, so the
-// last manual intent wins without an extra flag.
-export function applyTimeControls(input: SimControlsInput): Promise<schema.SimStateRow> {
+// Test-hook backing (FLIGHT_TEST_HOOKS=1 only — see app/api/test/set-timescale/route.ts): set the
+// effective time scale under the same lock as ticks so a background tick can never interleave
+// between read and write. Input validation happens in the route; this trusts its number.
+export function setTestTimeScale(scale: number): Promise<schema.SimStateRow> {
   return withLock(async () => {
     const inst = await getGameDb();
     await tickOnce(inst);
-    const sets: Partial<Pick<schema.SimStateRow, 'timeScale' | 'lastSelectedTimeScale' | 'paused'>> = {};
-    if (input.timeScale !== undefined) {
-      const scale = clampTimeScale(input.timeScale);
-      sets.timeScale = scale;
-      sets.lastSelectedTimeScale = scale;
-    }
-    if (input.paused !== undefined) sets.paused = input.paused;
-    if (Object.keys(sets).length > 0) await inst.db.update(schema.simState).set(sets);
+    await inst.db.update(schema.simState).set({ timeScale: scale });
     await persist(inst);
     const updated = (await inst.db.select().from(schema.simState))[0];
     if (!updated) throw new Error('sim_state row missing');
     return updated;
   });
 }
-
-export function clampTimeScale(v: number): number {
-  return Math.min(MAX_TIME_SCALE, Math.max(MIN_TIME_SCALE, v));
-}

lib/timeScale.test.ts

@@ -1,81 +0,0 @@
-import { describe, expect, it } from 'vitest';
-import { MAX_SCALE, MIN_SCALE, TIME_SCALES, scaleToSlider, sliderToScale } from './timeScale';
-
-const STEPS = TIME_SCALES.length - 1; // 9 intervals across the 10 ladder positions (v0.14.0)
-
-describe('sliderToScale', () => {
-  it('is exact at the endpoints (0 → 1×, 1 → 1000×)', () => {
-    expect(sliderToScale(0)).toBe(MIN_SCALE);
-    expect(sliderToScale(1)).toBe(MAX_SCALE);
-  });
-
-  it('maps each of the 10 positions to the ladder', () => {
-    const expected = [1, 2, 5, 10, 25, 50, 100, 250, 500, 1000];
-    for (let i = 0; i < TIME_SCALES.length; i++) {
-      expect(sliderToScale(i / STEPS)).toBe(expected[i]);
-    }
-  });
-
-  it('is monotonic non-decreasing across the whole range', () => {
-    let prev = sliderToScale(0);
-    for (let i = 1; i <= 2000; i++) {
-      const s = sliderToScale(i / 2000);
-      expect(s).toBeGreaterThanOrEqual(prev);
-      prev = s;
-    }
-  });
-
-  it('only ever returns a ladder value', () => {
-    for (let i = 0; i <= 2000; i++) {
-      expect(TIME_SCALES).toContain(sliderToScale(i / 2000));
-    }
-  });
-
-  it('clamps out-of-range and non-finite input', () => {
-    expect(sliderToScale(-0.5)).toBe(MIN_SCALE);
-    expect(sliderToScale(1.5)).toBe(MAX_SCALE);
-    expect(sliderToScale(NaN)).toBe(MIN_SCALE);
-  });
-});
-
-describe('scaleToSlider', () => {
-  it('is exact at the endpoints (1× → 0, 1000× → 1)', () => {
-    expect(scaleToSlider(1)).toBe(0);
-    expect(scaleToSlider(1000)).toBe(1);
-  });
-
-  it('places each ladder value on its own position', () => {
-    for (let i = 0; i < TIME_SCALES.length; i++) {
-      expect(scaleToSlider(TIME_SCALES[i])).toBeCloseTo(i / STEPS, 12);
-    }
-  });
-
-  it('stays within [0, 1] for in-range scales', () => {
-    for (let s = MIN_SCALE; s <= MAX_SCALE; s++) {
-      const t = scaleToSlider(s);
-      expect(t).toBeGreaterThanOrEqual(0);
-      expect(t).toBeLessThanOrEqual(1);
-    }
-  });
-
-  it('clamps out-of-range and non-finite input', () => {
-    expect(scaleToSlider(0)).toBe(0);
-    expect(scaleToSlider(-3)).toBe(0);
-    expect(scaleToSlider(1001)).toBe(1); // above the ladder top → clamped to 1000× → t=1
-    expect(scaleToSlider(NaN)).toBe(0);
-  });
-});
-
-describe('round-trip', () => {
-  it('sliderToScale(scaleToSlider(s)) === s for every ladder value', () => {
-    for (const s of TIME_SCALES) {
-      expect(sliderToScale(scaleToSlider(s))).toBe(s);
-    }
-  });
-
-  it('maps off-ladder scales to the nearest ladder step by log distance', () => {
-    expect(sliderToScale(scaleToSlider(3))).toBe(2); // ln 3 ≈ 1.10 → closer to 2 (ln ≈ 0.69) than 5 (ln ≈ 1.61)
-    expect(sliderToScale(scaleToSlider(60))).toBe(50); // legacy max from the v0.9.x era sits between 50 and 100, nearer 50
-    expect(sliderToScale(scaleToSlider(200))).toBe(250); // ln 200 ≈ 5.30 → closer to 250 (ln ≈ 5.52) than 100 (ln ≈ 4.61)
-  });
-});

lib/timeScale.ts

@@ -1,33 +0,0 @@
-// Pure mapping helpers for the time-scale slider (v0.9.2, values reworked in v0.14.0) — no
-// game logic, unit-testable in node. The slider has 10 discrete positions on a mixed
-// ×2/×2.5 ladder: 1× → 2× → 5× → 10× → 25× → 50× → 100× → 250× → 500× → 1000×, so each
-// step roughly doubles the speed (matching POST /api/sim's clamp range [1, 1000]).
-
-export const TIME_SCALES = [1, 2, 5, 10, 25, 50, 100, 250, 500, 1000] as const;
-export const MIN_SCALE: number = TIME_SCALES[0];
-export const MAX_SCALE: number = TIME_SCALES[TIME_SCALES.length - 1];
-
-const clamp = (v: number, lo: number, hi: number) => Math.min(hi, Math.max(lo, v));
-
-// t → scale: the position maps to the nearest ladder step. Exact at the endpoints:
-// sliderToScale(0) === 1, sliderToScale(1) === 1000.
-export function sliderToScale(t: number): number {
-  const tt = clamp(Number.isFinite(t) ? t : 0, 0, 1);
-  return TIME_SCALES[clamp(Math.round(tt * (TIME_SCALES.length - 1)), 0, TIME_SCALES.length - 1)];
-}
-
-// scale → t: the nearest ladder position by log distance. Exact at the endpoints:
-// scaleToSlider(1) === 0, scaleToSlider(1000) === 1; round-trips every value in TIME_SCALES.
-export function scaleToSlider(scale: number): number {
-  const s = clamp(Number.isFinite(scale) ? scale : MIN_SCALE, MIN_SCALE, MAX_SCALE);
-  let best = 0;
-  let bestDist = Infinity;
-  for (let i = 0; i < TIME_SCALES.length; i++) {
-    const d = Math.abs(Math.log(s) - Math.log(TIME_SCALES[i]));
-    if (d < bestDist) {
-      bestDist = d;
-      best = i;
-    }
-  }
-  return best / (TIME_SCALES.length - 1);
-}

lib/useGameState.test.ts

@@ -6,7 +6,7 @@ import { fetchState } from './useGameState';
 
 const SNAPSHOT = {
   account: { cash: 20_000, reputation: 10 },
-  simState: { clockMs: 1_750_000_000_000, timeScale: 1, paused: false },
+  simState: { clockMs: 1_750_000_000_000 },
   planes: [],
   packages: [],
 };

lib/useGameState.ts

@@ -28,7 +28,7 @@ export async function fetchState(): Promise<StateSnapshot> {
     (window as unknown as Record<string, unknown>).__flightLastSnapshot = {
       planeIds: snapshot.planes.map((p) => p.id),
       cash: snapshot.account.cash,
-      timeScale: snapshot.simState.timeScale,
+      clockMs: snapshot.simState.clockMs,
       at: Date.now(),
     };
   }

lib/useSimClock.test.ts

@@ -1,49 +1,45 @@
 import { describe, expect, it } from 'vitest';
 import { advanceSimClock, type SimClockAnchor } from './useSimClock';
+import { WORLD_TIME_SCALE } from './worldClock';
 
 // ISS-007 (v0.16.1) — the pure extrapolation core of lib/useSimClock.ts. The hook itself is a
 // thin setInterval + re-sync wrapper covered by e2e (panes.spec.ts "ticks smoothly between polls");
-// this suite pins the math: game time advances real-time × timeScale, frozen while paused.
+// this suite pins the math: game time advances real-time × WORLD_TIME_SCALE, frozen while idle.
 
 const anchor = (over: Partial<SimClockAnchor> = {}): SimClockAnchor => ({
   clockMs: 1_750_000_000_000,
   at: 1_000_000,
-  timeScale: 1,
-  paused: false,
+  advancing: true,
   ...over,
 });
 
 describe('advanceSimClock', () => {
-  it('advances by exactly elapsed real-time × timeScale while running', () => {
-    expect(advanceSimClock(anchor(), 1_001_000)).toBe(1_750_000_000_000 + 1_000); // scale 1: 1 s real = 1 s game
-    expect(advanceSimClock(anchor({ timeScale: 25 }), 1_002_500)).toBe(1_750_000_000_000 + 62_500);
-    // The e2e scenario: scale 1000, 2.5 s real → 2 500 game seconds.
-    expect(advanceSimClock(anchor({ timeScale: 1000 }), 1_002_500)).toBe(1_750_000_000_000 + 2_500_000);
+  it('advances by exactly elapsed real-time × WORLD_TIME_SCALE while running', () => {
+    expect(advanceSimClock(anchor(), 1_001_000)).toBe(1_750_000_000_000 + 1_000 * WORLD_TIME_SCALE);
+    // The e2e scenario: ~2.6 s real at the fixed world rate.
+    expect(advanceSimClock(anchor(), 1_002_600)).toBe(1_750_000_000_000 + 2_600 * WORLD_TIME_SCALE);
   });
 
   it('returns the anchor value exactly at zero elapsed', () => {
-    expect(advanceSimClock(anchor({ timeScale: 1000 }), 1_000_000)).toBe(1_750_000_000_000);
+    expect(advanceSimClock(anchor(), 1_000_000)).toBe(1_750_000_000_000);
   });
 
-  it('is frozen while paused regardless of elapsed or scale', () => {
-    const a = anchor({ timeScale: 1000, paused: true });
+  it('is frozen while idle regardless of elapsed time', () => {
+    const a = anchor({ advancing: false });
     expect(advanceSimClock(a, 1_000_000)).toBe(1_750_000_000_000);
     expect(advanceSimClock(a, 2_000_000)).toBe(1_750_000_000_000); // a full second later — still frozen
   });
 
   it('clamps to the anchor value when nowMs is before the anchor (clock skew), never backwards', () => {
-    expect(advanceSimClock(anchor({ timeScale: 1000 }), 999_999)).toBe(1_750_000_000_000);
-    expect(advanceSimClock(anchor({ paused: true }), 999_999)).toBe(1_750_000_000_000);
+    expect(advanceSimClock(anchor(), 999_999)).toBe(1_750_000_000_000);
+    expect(advanceSimClock(anchor({ advancing: false }), 999_999)).toBe(1_750_000_000_000);
   });
 
-  it('mirrors the server tick model (tickOnce): advance = elapsed × timeScale while actively polled', () => {
+  it('mirrors the server tick model (tickOnce): advance = elapsed × WORLD_TIME_SCALE while actively polled', () => {
     // lib/sim/engine.ts: clockMs += min(now − lastRealTickMs, MAX_TICK_ELAPSED_MS) × timeScale.
     // For gaps under the 2 s clamp the client extrapolation is exactly the server's own formula.
-    const scale = 50;
     for (const gap of [1, 250, 999, 1_999]) {
-      expect(advanceSimClock(anchor({ timeScale: scale }), 1_000_000 + gap)).toBe(
-        1_750_000_000_000 + gap * scale,
-      );
+      expect(advanceSimClock(anchor(), 1_000_000 + gap)).toBe(1_750_000_000_000 + gap * WORLD_TIME_SCALE);
     }
   });
 });

lib/useSimClock.ts

@@ -2,57 +2,51 @@
 
 import { useEffect, useRef, useState } from 'react';
 import type { StateSnapshot } from './game/state';
+import { WORLD_TIME_SCALE } from './worldClock';
 
 // ISS-007 (v0.16.1): the sim clock ticks smoothly on the CLIENT between polls instead of
-// jumping once per snapshot. The server's authoritative rate is exactly real-time × timeScale
+// jumping once per snapshot. The server's authoritative rate is exactly real-time × scale
 // (tickOnce in lib/sim/engine.ts: advance = min(elapsed, MAX_TICK_ELAPSED_MS) × timeScale), so
 // client-side extrapolation mirrors the server's own model. Every new snapshot re-anchors to
-// server truth, bounding any drift by network latency only.
+// server truth, bounding any drift by network latency only. ISS-117 (v0.52.0): the scale is the
+// fixed WORLD_TIME_SCALE and the clock freezes while nothing is happening — mirroring the
+// server's idle-pause instead of a player-controlled pause.
 
 export interface SimClockAnchor {
   // Server truth at anchor time — the snapshot's simState.clockMs.
   clockMs: number;
   // Date.now() when that snapshot was received.
   at: number;
-  timeScale: number;
-  paused: boolean;
+  // Whether the world clock is advancing (any plane flying or in repair).
+  advancing: boolean;
 }
 
-// Pure core of the extrapolation — mirrors tickOnce: while running, game time advances by
-// real-time × timeScale; while paused it is frozen (advance 0). nowMs before `at` clamps to
+// Pure core of the extrapolation — mirrors tickOnce: while advancing, game time advances by
+// real-time × WORLD_TIME_SCALE; while idle it is frozen (advance 0). nowMs before `at` clamps to
 // the anchor value instead of going backwards. Unit-testable in node.
 export function advanceSimClock(anchor: SimClockAnchor, nowMs: number): number {
-  if (anchor.paused) return anchor.clockMs;
-  return anchor.clockMs + Math.max(0, nowMs - anchor.at) * anchor.timeScale;
+  if (!anchor.advancing) return anchor.clockMs;
+  return anchor.clockMs + Math.max(0, nowMs - anchor.at) * WORLD_TIME_SCALE;
 }
 
 // ~10 fps display refresh — smooth for a seconds-precision wall clock without busy re-renders.
 const DISPLAY_TICK_MS = 100;
 
-export interface SimClockControls {
-  // EFFECTIVE controls (optimistic pending scale / current pause), not the snapshot's:
-  // UI changes take effect on click/drag without waiting for a confirming snapshot.
-  timeScale: number;
-  paused: boolean;
-}
-
 // Returns the display clockMs to render, or null until the first snapshot arrives.
-export function useSimClock(snapshot: StateSnapshot | null, controls: SimClockControls): number | null {
+export function useSimClock(snapshot: StateSnapshot | null): number | null {
   const anchorRef = useRef<SimClockAnchor | null>(null);
   const [displayMs, setDisplayMs] = useState<number | null>(null);
 
-  // Re-sync on every snapshot AND effective-control change: snap to server truth. The snapshot
-  // object is fresh per poll (useGameState), so this runs once per poll cycle as well.
+  // Re-sync on every snapshot: snap to server truth. The snapshot object is fresh per poll
+  // (useGameState), so this runs once per poll cycle as well.
   useEffect(() => {
     if (!snapshot) return;
-    anchorRef.current = {
-      clockMs: snapshot.simState.clockMs,
-      at: Date.now(),
-      timeScale: controls.timeScale,
-      paused: controls.paused,
-    };
+    // Mirror of the server's shouldAdvanceTime (lib/sim/engine.ts): frozen while no plane is
+    // flying or in repair. One line on purpose — keep it in sync with that function.
+    const advancing = snapshot.planes.some((p) => p.status === 'flying' || p.status === 'repairing');
+    anchorRef.current = { clockMs: snapshot.simState.clockMs, at: Date.now(), advancing };
     setDisplayMs(advanceSimClock(anchorRef.current, Date.now()));
-  }, [snapshot, controls.timeScale, controls.paused]);
+  }, [snapshot]);
 
   useEffect(() => {
     const id = setInterval(() => {

lib/worldClock.ts

@@ -0,0 +1,4 @@
+// ISS-117 (v0.52.0): the world clock runs at a fixed rate — no player-facing time controls.
+// Server-side the effective scale lives in the sim_state row (seeded to this value); client-side
+// lib/useSimClock.ts extrapolates between polls at this same constant, so keep them in sync here.
+export const WORLD_TIME_SCALE = 24;