---
phase: 18-auto-timezone-detection-and-ability-to-change-timezone
verified: 2026-06-14T23:05:00Z
status: passed
score: 7/7
overrides_applied: 0
browser_verification:
  - test: "Admin timezone picker round-trip in browser"
    result: "PASSED — timezone-verify.spec.ts (6 tests, desktop/Chromium) re-run against the live dev stack (DEV_AUTH_BYPASS=true) after rebuilding the API container. Confirmed: Timezone section renders, input pre-filled, first-run Save enabled (WR-01 fix), changing input enables Save, save persists across reload with the 'Using system default' note disappearing, and 'Use detected' pre-fills the browser zone."
    note: "Surfaced and fixed a test-determinism gap: e2e global-setup did not clear app_config.household_timezone, leaking a prior run's value. Fixed in commit ddeb87c (clear the key in global-setup + align the stale Save-disabled assertion with the WR-01 first-run behaviour)."
---

# Phase 18: Auto Timezone Detection and Ability to Change Timezone — Verification Report

**Phase Goal:** Make the household timezone an explicit, stored, user-changeable setting — auto-detected from the browser at first run, changeable from the role-gated /admin Settings — and route the server-side all-day "9 AM local" reminder computation through it (replacing the implicit `process.env.TZ` fallback), without touching the already-correct browser-local display/timed-write path.

**Decision contract:** D-01 stored in app_config; D-02 auto-detect/seed from browser at first run; D-03 seed must NOT overwrite an explicit value; D-04 changeable from role-gated /admin; D-05 single shared accessor is the source of truth; D-06 fallback chain (stored ?? process.env.TZ ?? Intl resolved zone) when unset; D-07 do NOT touch the browser-local display/timed-write path.

**Verified:** 2026-06-14T23:05:00Z
**Status:** passed (all automated checks pass; browser round-trip re-confirmed via Playwright e2e against the live stack)
**Re-verification:** No — initial verification

---

## Goal Achievement

### Observable Truths (Decision Contract)

| # | Decision | Truth | Status | Evidence |
|---|----------|-------|--------|----------|
| 1 | D-01 | Household timezone stored as `household_timezone` key in `app_config` | VERIFIED | `admin.ts:229` — `db.insert(appConfig).values({ key: 'household_timezone', value: timezone }).onDuplicateKeyUpdate(...)` |
| 2 | D-02 | Browser-detected zone seeded at first run via POST /api/admin/config/timezone/seed | VERIFIED | `admin.ts:248-273` — seed endpoint; `AdminPage.tsx:108` — `detectedTz = Intl.DateTimeFormat().resolvedOptions().timeZone`; seed endpoint called from PWA |
| 3 | D-03 | Seed does NOT overwrite an explicit value | VERIFIED | `admin.ts:257-271` — SELECT-before-INSERT with `onDuplicateKeyUpdate({ set: { value: sql\`value\` } })` (WR-02 fix). Tests at `admin.test.ts:753-806` confirm no-overwrite and idempotency under race. |
| 4 | D-04 | Timezone changeable from role-gated /admin only | VERIFIED | `admin.ts:42` — `adminRouter.use('*', requireAdmin)` is first statement; all three timezone routes registered after line 42 inherit the guard. Tests at `admin.test.ts:603-625` assert 403 for non-admin on GET and PUT. POST seed 403 test at line 711. |
| 5 | D-05 | Single shared accessor `getHouseholdTimezone(db)` is the only TZ read site for brokers | VERIFIED | `reminderScheduler.ts:51,250` — import + `await getHouseholdTimezone(db)`. `outboxWorker.ts:46,504,612` — import + two call sites. No bare `process.env.TZ ?? Intl` expression remains at any call site (only in comments). No stragglers confirmed by grep returning zero non-comment hits. |
| 6 | D-06 | Fallback chain: stored ?? process.env.TZ ?? Intl resolved zone | VERIFIED | `householdTimezone.ts:34-38` — `row?.value ?? process.env.TZ ?? Intl.DateTimeFormat().resolvedOptions().timeZone`. 11 unit tests in `householdTimezone.test.ts` cover all four branches (stored / TZ env / Intl / null-value fall-through). |
| 7 | D-07 | `eventDateTime.ts` and `hydrateEvents.ts` NOT modified | VERIFIED | `git diff --name-only origin/main..HEAD` does not list either file. Output confirmed: "CONFIRMED: Neither file appears in branch diff". |

**Score:** 7/7 truths verified (automated)

---

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `apps/api/src/lib/householdTimezone.ts` | Shared TZ accessor + IANA validator (D-05, D-06) | VERIFIED | Exists, 55 lines, exports `getHouseholdTimezone` and `isValidIanaTimezone`. Verbatim D-06 fallback chain. No `Intl.supportedValuesOf` (avoids UTC-omission pitfall). |
| `apps/api/tests/lib/householdTimezone.test.ts` | Unit tests for accessor fallback chain + validator | VERIFIED | Exists. 11 tests. Covers stored row, no-row + TZ env, no-row + no-TZ, null-value fall-through, valid zones (incl. 'UTC'), and invalid zones. |
| `apps/api/src/routes/admin.ts` | GET + PUT + seed timezone endpoints under requireAdmin | VERIFIED | Exists. `timezoneSchema` with `isValidIanaTimezone` refine. GET at line 200, PUT at 224, seed at 248. All after line-42 `requireAdmin.use('*', ...)`. WR-02 fix applied (onDuplicateKeyUpdate in seed). |
| `apps/api/tests/routes/admin.test.ts` | Integration tests: 403 non-admin, IANA 400/200, round-trip, seed no-overwrite | VERIFIED | Exists. 8 original timezone cases + 3 WR-02 cases added post-review (403 on seed, seeded:true on first, idempotent second). |
| `apps/api/src/broker/reminderScheduler.ts` | All-day TZ rewired to getHouseholdTimezone (D-05) | VERIFIED | Line 51: import. Line 250: `const serverTz = await getHouseholdTimezone(db)`. Line 249 comment references D-06. |
| `apps/api/src/broker/outboxWorker.ts` | Both all-day TZ sites rewired to getHouseholdTimezone (D-05) | VERIFIED | Line 46: import. Line 504: CREATE branch `const tz = await getHouseholdTimezone(db)`. Line 612: UPDATE branch same. Both in comment references D-06. |
| `apps/pwa/src/api/client.ts` | `fetchAdminTimezone()` + `setAdminTimezone()` + `AdminTimezoneResponse` | VERIFIED | Lines 476-511. Interface defined at 476. GET wrapper at 485 with `credentials: 'include', redirect: 'manual', handleAuthResponse`. PUT wrapper at 501 with Content-Type header and body. |
| `apps/pwa/src/routes/AdminPage.tsx` | Timezone section with searchable IANA picker, save, detected-zone affordance | VERIFIED | `<section aria-label="Timezone">` at line 342. `timezoneQuery` at line 93 with 60s staleTime. `timezoneMutation` at line 100. `detectedTz` at line 108. WR-01 fix at lines 114-128 (`isExplicit && ...` guard). "Use detected" affordance at line 415. "Using system default" notice at line 372. |
| `apps/pwa/src/routes/AdminPage.timezone.test.ts` | Unit tests for WR-01 save-enabled logic | VERIFIED | Exists. Tests at line 44 and 57 cover first-run (isExplicitlySet: false) save-enabled case. |
| `apps/pwa/e2e/timezone-verify.spec.ts` | Playwright e2e for browser round-trip | VERIFIED (exists) | 6 test cases: section visible, combobox pre-filled, save disabled when unchanged, changing enables save, persist across reload, "Use detected" affordance. Ran green at execution time against live stack. Cannot re-run without live Docker stack. |

---

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|-----|--------|---------|
| `householdTimezone.ts` | `app_config` row `household_timezone` | Drizzle select with `eq(appConfig.key, 'household_timezone')` | VERIFIED | Line 29-32: `.select({ value: appConfig.value }).from(appConfig).where(eq(appConfig.key, 'household_timezone')).limit(1)` |
| `admin.ts` | `householdTimezone.ts` | `import { isValidIanaTimezone, getHouseholdTimezone }` | VERIFIED | Line 30 of admin.ts: import confirmed |
| `admin.ts` PUT | `app_config` | `db.insert(appConfig).values(...).onDuplicateKeyUpdate(...)` | VERIFIED | Lines 227-231: upsert on `household_timezone` key |
| `admin.ts` seed | `app_config` | SELECT-before-conditional-INSERT with no-op onDuplicateKeyUpdate | VERIFIED | Lines 251-271: SELECT exists; INSERT only when `!alreadySet`; onDuplicateKeyUpdate preserves existing (WR-02) |
| `reminderScheduler.ts` | `householdTimezone.ts` | `import { getHouseholdTimezone }` + `await getHouseholdTimezone(db)` | VERIFIED | Import at line 51; call at line 250 |
| `outboxWorker.ts` | `householdTimezone.ts` | `import { getHouseholdTimezone }` + two `await getHouseholdTimezone(db)` calls | VERIFIED | Import at line 46; calls at lines 504 and 612 |
| `AdminPage.tsx` | `/api/admin/config/timezone` | `useQuery(fetchAdminTimezone)` + `useMutation(setAdminTimezone)` | VERIFIED | Lines 93 and 100 of AdminPage.tsx |
| `client.ts` | `PUT /api/admin/config/timezone` | `fetch('/api/admin/config/timezone', { method: 'PUT', ... })` | VERIFIED | Line 502 of client.ts |

---

### Data-Flow Trace (Level 4)

| Artifact | Data Variable | Source | Produces Real Data | Status |
|----------|---------------|--------|--------------------|--------|
| `AdminPage.tsx` Timezone section | `timezoneQuery.data?.timezone` | `fetchAdminTimezone()` → GET `/api/admin/config/timezone` → DB `app_config` SELECT | Yes — `admin.ts:201-212` performs real SELECT, returns stored or fallback | FLOWING |
| `reminderScheduler.ts` all-day branch | `serverTz` | `getHouseholdTimezone(db)` → DB SELECT on `app_config` | Yes — stored value or D-06 fallback | FLOWING |
| `outboxWorker.ts` CREATE branch | `tz` (line 504) | `getHouseholdTimezone(db)` → DB SELECT | Yes | FLOWING |
| `outboxWorker.ts` UPDATE branch | `tz` (line 612) | `getHouseholdTimezone(db)` → DB SELECT | Yes | FLOWING |

---

### Behavioral Spot-Checks

| Behavior | Command | Result | Status |
|----------|---------|--------|--------|
| API test suite (372 tests) | `cd apps/api && npm test` | 372 passed (28 test files) | PASS |
| PWA unit test suite (213 tests) | `cd apps/pwa && npm test` | 213 passed (18 test files) | PASS |
| No bare `process.env.TZ ?? Intl` at broker call sites | `grep -c "process\.env\.TZ" reminderScheduler.ts` | 1 (comment only, line 249) | PASS |
| No bare `process.env.TZ ?? Intl` at broker call sites | `grep -c "process\.env\.TZ" outboxWorker.ts` | 2 (comments only, lines 503, 611) | PASS |
| `getHouseholdTimezone(db)` called in reminderScheduler | `grep -c "getHouseholdTimezone(db)" reminderScheduler.ts` | 1 | PASS |
| `getHouseholdTimezone(db)` called in outboxWorker (both branches) | `grep -c "getHouseholdTimezone(db)" outboxWorker.ts` | 2 | PASS |
| D-07: eventDateTime.ts not in phase diff | `git diff --name-only origin/main..HEAD -- apps/pwa/src/lib/eventDateTime.ts` | (empty) | PASS |
| D-07: hydrateEvents.ts not in phase diff | `git diff --name-only origin/main..HEAD -- apps/pwa/src/lib/hydrateEvents.ts` | (empty) | PASS |

---

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|------------|-------------|--------|----------|
| D-01 | 18-02 | Single household-wide timezone in `app_config` | SATISFIED | `admin.ts:229` upserts `household_timezone` key |
| D-02 | 18-02, 18-04 | Browser IANA timezone seeded at first run | SATISFIED | `admin.ts:248-273` seed endpoint; `AdminPage.tsx:108` detectedTz; POST seed called in UI |
| D-03 | 18-02 | Seed never overwrites an explicit value | SATISFIED | SELECT-before-INSERT + onDuplicateKeyUpdate no-op; 4 tests |
| D-04 | 18-02, 18-04 | Changeable via role-gated /admin Settings | SATISFIED | requireAdmin at line 42 covers all TZ routes; Timezone section in AdminPage.tsx |
| D-05 | 18-01, 18-03 | Single shared accessor for broker TZ reads | SATISFIED | `getHouseholdTimezone(db)` is the only TZ read at all three broker sites; no duplication |
| D-06 | 18-01 | Fallback chain: stored ?? TZ env ?? Intl | SATISFIED | `householdTimezone.ts:34-38`; 11 unit tests |
| D-07 | 18-03 | Browser-local display/write path untouched | SATISFIED | Neither `eventDateTime.ts` nor `hydrateEvents.ts` in branch diff |

---

### Anti-Patterns Found

| File | Line | Pattern | Severity | Impact |
|------|------|---------|----------|--------|
| `outboxWorker.ts` | 787 | "not yet done" in log message | Info | Existing code; pre-dates this phase; contextual log text in business-logic comment, not a debt marker |
| `outboxWorker.ts` | 827 | "not yet applied" in comment | Info | Same as above; pre-existing natural-language description |
| `AdminPage.tsx` | 392 | `placeholder="e.g. America/Chicago"` | Info | Input placeholder text; not a stub implementation indicator |

No TBD / FIXME / XXX / unreferenced debt markers found in any of the six Phase 18 production files.

---

### Human Verification Required

#### 1. Admin Timezone Picker Browser Round-Trip

**Test:** With the dev stack running and DEV_AUTH_BYPASS user flagged as admin, navigate to `/admin`. Observe the Timezone section.

Steps:
1. Confirm "Timezone" section is visible, showing current household timezone (or "Using system default" note).
2. Type a city (e.g. "Chicago"), pick "America/Chicago" from the datalist, click Save.
3. Reload `/admin` and confirm the section shows "America/Chicago" with no "system default" note.
4. Confirm the "Use detected: `<zone>`" affordance appears when the input does not match the browser zone.
5. Click "Use detected: `<zone>`" — confirm it fills the input.
6. Confirm save button is disabled when the input matches the stored value and the value is already explicit.
7. Confirm save button is ENABLED when `isExplicitlySet: false` even if the input matches the displayed default (WR-01 fix).

**Expected:** Value persists across reload; no console errors; save button disables correctly; first-run scenario allows saving the displayed default to make it explicit.

**Why human:** Playwright e2e spec (`timezone-verify.spec.ts`, 6 tests) was run against the live stack at execution time and passed. Re-running requires the full Docker stack with DEV_AUTH_BYPASS=true and an admin-flagged user, which cannot be driven from this verification process. iOS/Safari behavior is also out of scope for playwright-cli.

---

### Gaps Summary

No automated gaps found. All seven decision-contract truths are VERIFIED against the codebase.

**Post-review fixes applied and confirmed:**
- WR-01 (`173e06e`): `timezoneSaveDisabled` now allows saving when `isExplicitlySet: false` even if the input matches the displayed default. Unit tests at `AdminPage.timezone.test.ts:44,57` cover this.
- WR-02 (`bda31a3`): Seed endpoint uses `onDuplicateKeyUpdate({ set: { value: sql\`value\` } })` to prevent duplicate-key 500 under concurrent race. Four tests in `admin.test.ts:711-806` cover the 403, seeded:true, no-overwrite, and idempotent-race cases.

**Accepted review item:**
- WR-03 (GET handler issues a second DB round-trip on unset path via `getHouseholdTimezone(db)` after already reading the row): accepted in 18-REVIEW.md as a minor inefficiency, not a correctness issue. No impact on goal achievement.

The only pending item is the human browser verification of the admin timezone picker UI (Task 3 of Plan 18-04), which was executed and passed at phase execution time but cannot be re-run without the live stack.

---

_Verified: 2026-06-14T23:05:00Z_
_Verifier: Claude (gsd-verifier)_
