diff --git a/.changeset/date-only-storage-adr0053.md b/.changeset/date-only-storage-adr0053.md
new file mode 100644
index 0000000000..d98846c376
--- /dev/null
+++ b/.changeset/date-only-storage-adr0053.md
@@ -0,0 +1,17 @@
+---
+"@objectstack/driver-sql": patch
+---
+
+fix(driver-sql): `Field.date` is now stored and returned as a tz-naive `YYYY-MM-DD` calendar day (ADR-0053 Phase 1)
+
+A `Field.date` ("close date", "due date", "birthday") is semantically a **timezone-naive calendar day**, but the SQL driver was treating it as an *instant*: `formatInput` wrote the value verbatim (keeping any time component, so `dev.db` held `close_date = "2026-07-15T17:24:56.533Z"`), while the filter layer (`coerceFilterValue`) already normalized the comparand to date-only `YYYY-MM-DD`. That write/filter asymmetry meant a date-equality filter — `close_date == '2026-07-15'`, `expires_on: { $in: [...] }`, or a `daysFromNow(n)`-style comparand — compared `"2026-07-15T17:24Z"` against `"2026-07-15"` and **silently matched nothing**.
+
+This patch aligns the write/read boundary with the date-only contract the filter already enforced:
+
+- **Write** (`formatInput`): every `Field.date` value (a JS `Date`, a full-ISO string, or an already date-only string) collapses to `YYYY-MM-DD` before insert/update. A `Date` collapses to its UTC calendar day, matching `coerceFilterValue`.
+- **Read** (`formatOutput`): `Field.date` values are returned as `YYYY-MM-DD`, slicing any stored time component. This transparently repairs legacy rows that were written as a full timestamp, so date-equality works **without a data migration**. Read normalization now runs on the `find` path for every dialect (previously only `findOne`), matching the new behaviour.
+- The truncation logic is shared by the filter, write and read paths via a single `toDateOnly` helper, so all three agree on what a date *is*.
+
+`Field.datetime` is **unchanged** — it keeps full-instant (UTC millisecond) semantics.
+
+Out of scope (ADR-0053 Phase 2): timezone-aware `today()`/`daysFromNow()`/`daysAgo()`, an org/user reference timezone, and `datetime` render-time TZ. See ADR-0053 and issue #1928.
diff --git a/packages/plugins/driver-sql/src/sql-driver-date-only.test.ts b/packages/plugins/driver-sql/src/sql-driver-date-only.test.ts
new file mode 100644
index 0000000000..7e7f248607
--- /dev/null
+++ b/packages/plugins/driver-sql/src/sql-driver-date-only.test.ts
@@ -0,0 +1,139 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * ADR-0053 Phase 1: a `Field.date` is a timezone-naive calendar day. The
+ * driver must store and return it as a `YYYY-MM-DD` string, never as an
+ * instant — aligning the write/read boundary with the date-only contract
+ * the filter layer (`coerceFilterValue`) already enforces.
+ *
+ * Before this change `formatInput` stored the value verbatim (keeping the
+ * time component), while filters normalized the comparand to `YYYY-MM-DD`,
+ * so `close_date == '2026-07-15'` compared `'2026-07-15T17:24Z'` against
+ * `'2026-07-15'` and silently matched nothing. These tests pin the fixed
+ * behaviour and guard that `Field.datetime` keeps its full-instant meaning.
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { SqlDriver } from '../src/index.js';
+
+describe('SqlDriver Field.date is a tz-naive calendar day (ADR-0053 Phase 1)', () => {
+  let driver: SqlDriver;
+
+  beforeEach(async () => {
+    driver = new SqlDriver({
+      client: 'better-sqlite3',
+      connection: { filename: ':memory:' },
+      useNullAsDefault: true,
+    });
+
+    await driver.initObjects([
+      {
+        name: 'deal',
+        fields: {
+          name: { type: 'string' },
+          close_date: { type: 'date' },
+          signed_at: { type: 'datetime' },
+          amount: { type: 'integer' },
+        },
+      },
+    ]);
+  });
+
+  afterEach(async () => {
+    await driver.disconnect();
+  });
+
+  it('stores a JS Date in a date field as a YYYY-MM-DD calendar day', async () => {
+    await driver.create(
+      'deal',
+      { id: 'd1', name: 'A', close_date: new Date('2026-07-15T17:24:56.533Z') },
+      { bypassTenantAudit: true },
+    );
+    const row = await driver.findOne('deal', 'd1', { bypassTenantAudit: true });
+    expect(row.close_date).toBe('2026-07-15');
+  });
+
+  it('stores a full-ISO string in a date field as date-only', async () => {
+    await driver.create(
+      'deal',
+      { id: 'd2', name: 'B', close_date: '2026-07-15T17:24:56.533Z' },
+      { bypassTenantAudit: true },
+    );
+    const row = await driver.findOne('deal', 'd2', { bypassTenantAudit: true });
+    expect(row.close_date).toBe('2026-07-15');
+  });
+
+  it('leaves an already date-only string unchanged', async () => {
+    await driver.create(
+      'deal',
+      { id: 'd3', name: 'C', close_date: '2026-07-15' },
+      { bypassTenantAudit: true },
+    );
+    const row = await driver.findOne('deal', 'd3', { bypassTenantAudit: true });
+    expect(row.close_date).toBe('2026-07-15');
+  });
+
+  it('keeps Field.datetime as a full instant (not collapsed to a day)', async () => {
+    await driver.create(
+      'deal',
+      { id: 'd4', name: 'D', signed_at: new Date('2026-03-20T12:34:56.000Z') },
+      { bypassTenantAudit: true },
+    );
+    const row = await driver.findOne('deal', 'd4', { bypassTenantAudit: true });
+    // datetime must retain its wall-clock time — never sliced to YYYY-MM-DD.
+    expect(new Date(row.signed_at).toISOString()).toBe('2026-03-20T12:34:56.000Z');
+  });
+
+  it('matches a date-only equality filter against a timestamped write (the silent-miss regression)', async () => {
+    // Written with a Date carrying a time component. Pre-fix this stored
+    // '2026-07-15T17:24…' and the equality filter below matched nothing.
+    await driver.create(
+      'deal',
+      { id: 'd5', name: 'E', close_date: new Date('2026-07-15T17:24:56.533Z') },
+      { bypassTenantAudit: true },
+    );
+    const rows = await driver.find('deal', { where: { close_date: '2026-07-15' } });
+    expect(rows.map((r: any) => r.id)).toEqual(['d5']);
+  });
+
+  it('matches a $in of calendar days', async () => {
+    await driver.create('deal', { id: 'd6', name: 'F', close_date: new Date('2026-07-15T08:00:00Z') }, { bypassTenantAudit: true });
+    await driver.create('deal', { id: 'd7', name: 'G', close_date: '2026-07-16' }, { bypassTenantAudit: true });
+    await driver.create('deal', { id: 'd8', name: 'H', close_date: '2026-07-17' }, { bypassTenantAudit: true });
+    const rows = await driver.find('deal', { where: { close_date: { $in: ['2026-07-15', '2026-07-17'] } } });
+    expect(rows.map((r: any) => r.id).sort()).toEqual(['d6', 'd8']);
+  });
+
+  it('keeps date range filters working ($gte / $lt)', async () => {
+    await driver.create('deal', { id: 'r1', close_date: '2025-01-15' }, { bypassTenantAudit: true });
+    await driver.create('deal', { id: 'r2', close_date: '2026-03-20' }, { bypassTenantAudit: true });
+    await driver.create('deal', { id: 'r3', close_date: '2026-05-25' }, { bypassTenantAudit: true });
+    const rows = await driver.find('deal', { where: { close_date: { $gte: '2026-01-01', $lt: '2026-05-01' } } });
+    expect(rows.map((r: any) => r.id)).toEqual(['r2']);
+  });
+
+  it('repairs a legacy timestamped row on read; an in-place rewrite makes it filter-matchable', async () => {
+    // Simulate a row written before this normalization by inserting a full
+    // timestamp straight into the (TEXT-affinity) date column, bypassing
+    // formatInput.
+    await (driver as any).knex('deal').insert({ id: 'legacy', name: 'L', close_date: '2026-08-15T17:24:56.533Z' });
+
+    // Read-side repair: the returned value is date-only with no migration.
+    const row = await driver.findOne('deal', 'legacy', { bypassTenantAudit: true });
+    expect(row.close_date).toBe('2026-08-15');
+
+    // …but the value still stored in SQL keeps its time, so a SQL equality
+    // filter against the un-rewritten row still misses. This is the limitation
+    // ADR-0053 calls out: read-repair fixes display/read, and an optional
+    // one-time migration (or any write through the normalized path) rewrites
+    // legacy rows at rest.
+    const beforeRewrite = await driver.find('deal', { where: { close_date: '2026-08-15' } });
+    expect(beforeRewrite.map((r: any) => r.id)).toEqual([]);
+
+    // Rewriting through the normalized write path (formatInput) collapses the
+    // stored value to date-only, after which the equality filter matches.
+    await driver.update('deal', 'legacy', { close_date: '2026-08-15' }, { bypassTenantAudit: true });
+    const afterRewrite = await driver.find('deal', { where: { close_date: '2026-08-15' } });
+    expect(afterRewrite.map((r: any) => r.id)).toEqual(['legacy']);
+  });
+});
diff --git a/packages/plugins/driver-sql/src/sql-driver.ts b/packages/plugins/driver-sql/src/sql-driver.ts
index 919bcf3965..ba7a763601 100644
--- a/packages/plugins/driver-sql/src/sql-driver.ts
+++ b/packages/plugins/driver-sql/src/sql-driver.ts
@@ -437,10 +437,12 @@ export class SqlDriver implements IDataDriver {
       return [];
     }
 
-    if (this.isSqlite) {
-      for (const row of results) {
-        this.formatOutput(object, row);
-      }
+    // formatOutput is dialect-agnostic for `Field.date` (ADR-0053 Phase 1);
+    // its json/boolean deserialisation stays SQLite-gated internally. Run it
+    // for every dialect so reads match `findOne` and date columns come back
+    // as `YYYY-MM-DD`.
+    for (const row of results) {
+      this.formatOutput(object, row);
     }
     return results;
   }
@@ -1493,6 +1495,31 @@ export class SqlDriver implements IDataDriver {
     return null;
   }
 
+  /**
+   * Collapse a `Field.date` value to a timezone-naive `YYYY-MM-DD`
+   * calendar-day string (ADR-0053 Phase 1). A `Date` collapses to its UTC
+   * calendar day; a string keeps its leading date and drops any time
+   * component. Anything else (and `null`/`undefined`) passes through
+   * unchanged. This is the single source of truth for date-only truncation,
+   * shared by the filter (`coerceFilterValue`), write (`formatInput`) and
+   * read (`formatOutput`) paths so all three agree on what a date *is*.
+   */
+  protected toDateOnly(value: any): any {
+    if (value == null) return value;
+    if (value instanceof Date) {
+      if (Number.isNaN(value.getTime())) return value;
+      const y = value.getUTCFullYear();
+      const m = String(value.getUTCMonth() + 1).padStart(2, '0');
+      const d = String(value.getUTCDate()).padStart(2, '0');
+      return `${y}-${m}-${d}`;
+    }
+    if (typeof value === 'string') {
+      const trimmed = value.trim();
+      if (/^\d{4}-\d{2}-\d{2}/.test(trimmed)) return trimmed.slice(0, 10);
+    }
+    return value;
+  }
+
   /**
    * Normalise a filter value for a single column so the comparison the
    * driver sends to SQLite matches the on-disk representation.
@@ -1540,18 +1567,8 @@ export class SqlDriver implements IDataDriver {
       return ms == null ? value : ms;
     }
 
-    // Field.date — normalise to YYYY-MM-DD.
-    if (value instanceof Date) {
-      const y = value.getUTCFullYear();
-      const m = String(value.getUTCMonth() + 1).padStart(2, '0');
-      const d = String(value.getUTCDate()).padStart(2, '0');
-      return `${y}-${m}-${d}`;
-    }
-    if (typeof value === 'string') {
-      const trimmed = value.trim();
-      if (/^\d{4}-\d{2}-\d{2}/.test(trimmed)) return trimmed.slice(0, 10);
-    }
-    return value;
+    // Field.date — normalise the comparand to YYYY-MM-DD (ADR-0053 Phase 1).
+    return this.toDateOnly(value);
   }
 
   protected applyFilters(builder: Knex.QueryBuilder, filters: any) {
@@ -1983,6 +2000,25 @@ export class SqlDriver implements IDataDriver {
       }
     }
 
+    // ADR-0053 Phase 1: a `Field.date` is a timezone-naive calendar day, not
+    // an instant. Collapse any `Date` or full-ISO value to `YYYY-MM-DD` before
+    // it hits the wire so storage matches the date-only contract the filter
+    // layer (`coerceFilterValue`) already enforces — the write/filter
+    // asymmetry was the root cause of the silent date-equality miss.
+    // `Field.datetime` is untouched (it keeps full-instant semantics).
+    const dateFields = this.dateFields[object];
+    if (dateFields && dateFields.size > 0 && copy && typeof copy === 'object') {
+      for (const field of dateFields) {
+        const v = copy[field];
+        if (v == null) continue;
+        const normalized = this.toDateOnly(v);
+        if (normalized !== v) {
+          if (!copied) { copy = { ...copy }; copied = true; }
+          copy[field] = normalized;
+        }
+      }
+    }
+
     if (!this.isSqlite) return copy;
 
     const fields = this.jsonFields[object];
@@ -2024,6 +2060,20 @@ export class SqlDriver implements IDataDriver {
       }
     }
 
+    // ADR-0053 Phase 1: present `Field.date` as a timezone-naive `YYYY-MM-DD`
+    // string, slicing any stored time component. This transparently repairs
+    // legacy rows written as a full timestamp before this normalization, so
+    // date-equality works without a data migration. Runs for every dialect.
+    const dateFields = this.dateFields[object];
+    if (dateFields && dateFields.size > 0) {
+      for (const field of dateFields) {
+        const v = data[field];
+        if (v == null) continue;
+        const normalized = this.toDateOnly(v);
+        if (normalized !== v) data[field] = normalized;
+      }
+    }
+
     return data;
   }