diff --git a/.changeset/22301-seed-temporal-stored-form.md b/.changeset/22301-seed-temporal-stored-form.md
new file mode 100644
index 00000000000..5ddbe5b797c
--- /dev/null
+++ b/.changeset/22301-seed-temporal-stored-form.md
@@ -0,0 +1,16 @@
+---
+'@objectstack/metadata-protocol': patch
+---
+
+A cel-dated seed row reaches every hook in the stored form of its temporal field
+
+Clause-②: no
+
+`` cel`daysFromNow(n)` ``, `daysAgo(n)`, `today()` and `now()` in a seed record resolve to a JS `Date`. The seed loader handed that `Date` to the engine, so what a hook saw depended on how the hook ran:
+
+- An in-process `handler` (a source config, which `@objectstack/verify`'s `bootStack` boots) saw the `Date` object.
+- A sandboxed `body` (the compiled artifact `objectstack dev` boots) saw a full ISO instant, even on a `date` field.
+
+A hook that reads a date field as a string therefore accepted the row under `objectstack dev` and refused it under `bootStack`, and the row was not stored.
+
+The loader now puts each `Date` on a `date`, `datetime` or `time` field into the stored form the drivers write (`YYYY-MM-DD`, the UTC ISO instant, `HH:MM:SS`) before any hook runs, so every hook sees the value the column stores. A body hook on a `date` field now sees `2026-10-09` where it saw `2026-10-09T00:00:00.000Z`. Stored values do not change on any driver, because each driver already normalises a declared temporal field on write (`@objectstack/driver-memory` through the same `temporalStorageForm`). A `Date` on a field that is not temporal, or on a field the object does not declare, is handed over unchanged.
diff --git a/packages/metadata-protocol/src/seed-loader.ts b/packages/metadata-protocol/src/seed-loader.ts
index c0e971714f2..097d4adee50 100644
--- a/packages/metadata-protocol/src/seed-loader.ts
+++ b/packages/metadata-protocol/src/seed-loader.ts
@@ -23,7 +23,10 @@ import {
 } from '@objectstack/spec/data';
 import { SEED_WRITE_EXECUTION_CONTEXT } from '@objectstack/spec/kernel';
 import { resolveSeedRecord } from '@objectstack/formula';
-import { bulkWrite, withTransientRetry, defaultIsTransientError, type BulkWriteRowResult, runWithAdvisoryAggregation, type AdvisoryGroup } from '@objectstack/core';
+import {
+  bulkWrite, withTransientRetry, defaultIsTransientError, type BulkWriteRowResult, runWithAdvisoryAggregation, type AdvisoryGroup,
+  temporalComparandKind, temporalStorageForm,
+} from '@objectstack/core';
 // [#8442] The repo's ONE recogniser for "this throw is a record-validation
 // failure" — duck-typed on `code`/`name`, the same predicate `mapDataError` and
 // both dispatcher error exits use. Imported rather than re-spelled so the seed
@@ -440,6 +443,39 @@ function seedRowNeedsOrganization(definition: unknown): boolean {
   return resolveInjectedSystemColumns(definition).tenant;
 }
 
+/**
+ * [#22301] Put every `Date` a seed row resolved to into the STORED form of its
+ * temporal field, before the row reaches the engine.
+ *
+ * `resolveSeedRecord` evaluates an Expression envelope to whatever the CEL
+ * stdlib returns, and `today()` / `daysFromNow(n)` / `daysAgo(n)` / `now()`
+ * return a JS `Date` (ADR-0053 D1). Handed on as a `Date`, what a hook saw
+ * depended on HOW the hook ran, not on the value: a hook lowered to a body runs
+ * in the sandbox, whose JSON bridge turned it into a full ISO instant
+ * (`2026-10-09T00:00:00.000Z`, even on a `date` field), and the same hook as an
+ * in-process `handler` (a source config, as `@objectstack/verify`'s `bootStack`
+ * boots it) received the `Date` object itself. A hook reading the field as a
+ * string accepted the row under `os dev` and refused it under `bootStack`.
+ * Neither is the value the column stores — the driver writes the ADR-0053 form
+ * (`YYYY-MM-DD` for a `date`) — nor the value a REST write of the same row
+ * hands the hook.
+ *
+ * So the row leaves the loader in that stored form, by the ONE rule the drivers
+ * apply on write (`temporalStorageForm`, `@objectstack/core`): every hook sees
+ * what is stored, however it runs. A non-temporal field, a field the definition
+ * does not declare, and an Invalid Date are left exactly as resolved — the rule
+ * normalizes temporal FORM and never invents a value (its own totality).
+ */
+function seedValuesInStoredForm(record: Record<string, unknown>, definition: unknown): void {
+  const fields = (definition as { fields?: Record<string, { type?: unknown } | undefined> } | null | undefined)?.fields;
+  if (!fields || typeof fields !== 'object') return;
+  for (const [key, value] of Object.entries(record)) {
+    if (!(value instanceof Date)) continue;
+    const kind = temporalComparandKind(fields[key]?.type);
+    if (kind) record[key] = temporalStorageForm(value, kind);
+  }
+}
+
 export class SeedLoaderService implements ISeedLoaderService {
   private engine: IDataEngine;
   private metadata: IMetadataService;
@@ -1248,6 +1284,8 @@ export class SeedLoaderService implements ISeedLoaderService {
         continue;
       }
       const record = { ...(seedResult.value as Record<string, unknown>) };
+      // [#22301] The stored form, not a `Date`, before any hook can see it.
+      seedValuesInStoredForm(record, objectDefinition);
       /**
        * [commit 1cba33f16] Deferrals this row took on a column the write contract
        * requires on insert. Collected during resolution, reported once the
diff --git a/packages/verify/src/harness.seed-temporal-form.test.ts b/packages/verify/src/harness.seed-temporal-form.test.ts
new file mode 100644
index 00000000000..7461ae63ab4
--- /dev/null
+++ b/packages/verify/src/harness.seed-temporal-form.test.ts
@@ -0,0 +1,147 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * #22301 item 9 — a cel-dated seed row is stored under `bootStack`, and every
+ * hook sees the value the column stores, however the hook runs.
+ *
+ * Measured before the fix (`origin/main` 28bff18d0, this file's app, one
+ * `bootStack`): for `start_date: cel\`daysFromNow(1)\`` on a `date` field the
+ * SQL driver stored `YYYY-MM-DD`, while
+ *
+ *   · an in-process `handler` hook (a source config — what `bootStack` boots)
+ *     saw a JS `Date` object, and
+ *   · the same hook lowered to a sandboxed `body` (the compiled artifact
+ *     `objectstack dev` boots) saw the full instant `YYYY-MM-DDT00:00:00.000Z`.
+ *
+ * So a hook that reads the field as a string — hotcrm's `campaign_validation`
+ * is the measured one — accepted the row under `objectstack dev` and refused it
+ * under `bootStack`. The divergence was the value the seed loader handed the
+ * engine (`resolveSeedRecord`'s `Date`), not the app's hook: the loader now
+ * hands over the ADR-0053 stored form, and every reading below is equal.
+ *
+ * The literal rows are the control: a literal ISO value is already in stored
+ * form and reaches every hook unchanged.
+ */
+
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { cel, defineStack } from '@objectstack/spec';
+import { Field, ObjectSchema } from '@objectstack/spec/data';
+import { bootStack, type VerifyStack } from './harness.js';
+
+/** What the in-process hook saw, per row name: `typeof` and the value. */
+const handlerSaw = new Map<string, { start: string; end: string }>();
+const describeValue = (v: unknown): string =>
+  v instanceof Date ? `Date:${v.toISOString()}` : `${typeof v}:${String(v)}`;
+
+const fields = {
+  name: Field.text({ label: 'Name', required: true }),
+  start_date: Field.date({ label: 'Start' }),
+  end_at: Field.datetime({ label: 'End' }),
+  seen: Field.text({ label: 'Seen' }),
+};
+
+const rows = (prefix: string) => [
+  { name: `${prefix}-cel`, start_date: cel`daysFromNow(1)`, end_at: cel`daysFromNow(2)` },
+  { name: `${prefix}-literal`, start_date: '2026-10-10', end_at: '2026-10-11T00:00:00.000Z' },
+];
+
+const app = defineStack({
+  manifest: { id: 'com.example.stf', namespace: 'stf', version: '0.0.0', type: 'app', name: 'Seed temporal form' },
+  objects: [
+    ObjectSchema.create({ name: 'stf_handler', label: 'Handler', pluralLabel: 'Handlers', sharingModel: 'public_read_write', fields }),
+    ObjectSchema.create({ name: 'stf_body', label: 'Body', pluralLabel: 'Bodies', sharingModel: 'public_read_write', fields }),
+    ObjectSchema.create({ name: 'stf_guarded', label: 'Guarded', pluralLabel: 'Guarded', sharingModel: 'public_read_write', fields }),
+  ],
+  hooks: [
+    {
+      name: 'stf_handler_reads',
+      object: 'stf_handler',
+      events: ['beforeInsert'],
+      handler: async (ctx: { input: Record<string, unknown> }) => {
+        handlerSaw.set(String(ctx.input.name), {
+          start: describeValue(ctx.input.start_date),
+          end: describeValue(ctx.input.end_at),
+        });
+      },
+    },
+    {
+      name: 'stf_body_reads',
+      object: 'stf_body',
+      events: ['beforeInsert'],
+      body: {
+        language: 'js',
+        source:
+          "ctx.input.seen = typeof ctx.input.start_date + ':' + String(ctx.input.start_date) + '|' + " +
+          "typeof ctx.input.end_at + ':' + String(ctx.input.end_at);",
+        capabilities: [],
+      },
+    },
+    {
+      // hotcrm's `campaign_validation` shape: dates are read only when strings.
+      name: 'stf_guarded_requires_string_dates',
+      object: 'stf_guarded',
+      events: ['beforeInsert'],
+      handler: async (ctx: { input: Record<string, unknown> }) => {
+        if (typeof ctx.input.start_date !== 'string' || typeof ctx.input.end_at !== 'string') {
+          throw Object.assign(new Error('both dates are required'), { code: 'VALIDATION_FAILED', status: 400 });
+        }
+      },
+    },
+  ],
+  data: [
+    { object: 'stf_handler', mode: 'insert', records: rows('handler') },
+    { object: 'stf_body', mode: 'insert', records: rows('body') },
+    { object: 'stf_guarded', mode: 'insert', records: rows('guarded') },
+  ],
+} as never);
+
+let stack: VerifyStack;
+const stored = new Map<string, Record<string, unknown>>();
+
+beforeAll(async () => {
+  stack = await bootStack(app);
+  for (const object of ['stf_handler', 'stf_body', 'stf_guarded']) {
+    for (const row of await stack.rows(object)) stored.set(String(row.name), row);
+  }
+}, 120_000);
+afterAll(async () => {
+  await stack?.stop();
+});
+
+describe('a cel-dated seed row reaches every hook in its stored form', () => {
+  it('the rows are stored, in the ADR-0053 form of each field', () => {
+    for (const prefix of ['handler', 'body', 'guarded']) {
+      const row = stored.get(`${prefix}-cel`);
+      expect(row, `${prefix}-cel stored`).toBeDefined();
+      expect(row!.start_date).toMatch(/^\d{4}-\d{2}-\d{2}$/);
+      expect(row!.end_at).toMatch(/^\d{4}-\d{2}-\d{2}T00:00:00\.000Z$/);
+    }
+  });
+
+  it('an in-process handler sees the stored string, not a Date', () => {
+    const row = stored.get('handler-cel')!;
+    expect(handlerSaw.get('handler-cel')).toEqual({
+      start: `string:${row.start_date}`,
+      end: `string:${row.end_at}`,
+    });
+  });
+
+  it('a sandboxed body sees the same value — the stored form, not a full instant on a date field', () => {
+    const row = stored.get('body-cel')!;
+    expect(row.seen).toBe(`string:${row.start_date}|string:${row.end_at}`);
+  });
+
+  it('a hook that reads the dates only as strings no longer refuses the row', () => {
+    expect(stored.get('guarded-cel')).toBeDefined();
+  });
+
+  it('control — a literal row reaches both hooks unchanged and is stored as written', () => {
+    expect(handlerSaw.get('handler-literal')).toEqual({
+      start: 'string:2026-10-10',
+      end: 'string:2026-10-11T00:00:00.000Z',
+    });
+    expect(stored.get('body-literal')!.seen).toBe('string:2026-10-10|string:2026-10-11T00:00:00.000Z');
+    expect(stored.get('handler-literal')).toMatchObject({ start_date: '2026-10-10', end_at: '2026-10-11T00:00:00.000Z' });
+    expect(stored.get('guarded-literal')).toBeDefined();
+  });
+});