@@ -109,18 +109,17 @@ describe('parseDateCell — an offset-free datetime cell reads in the business t
     expect(parseDateCell('2026-01-15 12:00:00', 'datetime', NEW_YORK)).toBe('2026-01-15T17:00:00.000Z');
   });
 
-  it('accepts the ISO and export shapes (T or space, optional seconds/millis)', () => {
+  it('accepts the shapes a spreadsheet actually writes (T or space, optional seconds/millis, slashes)', () => {
     process.env.TZ = 'America/Los_Angeles';
     expect(parseDateCell('2026-08-01T06:00:00', 'datetime', SHANGHAI)).toBe(CROSS_MONTH_UTC);
     expect(parseDateCell('2026-08-01 06:00', 'datetime', SHANGHAI)).toBe(CROSS_MONTH_UTC);
+    expect(parseDateCell('2026/08/01 06:00:00', 'datetime', SHANGHAI)).toBe(CROSS_MONTH_UTC);
     expect(parseDateCell('2026-08-01 06:00:00.123', 'datetime', SHANGHAI)).toBe('2026-07-31T22:00:00.123Z');
   });
 
   it('an unparseable cell is still a coercion failure, not an invalid instant', () => {
     expect(parseDateCell('not a date', 'datetime', SHANGHAI)).toBeUndefined();
     expect(parseDateCell('2026-13-45 99:00:00', 'datetime', SHANGHAI)).toBeUndefined();
-    // [#20534] Neither ISO 8601 nor the export shape: refused, not read.
-    expect(parseDateCell('2026/08/01 06:00:00', 'datetime', SHANGHAI)).toBeUndefined();
   });
 });
 
 
@@ -84,6 +84,7 @@ describe('parseNumberCell', () => {
 describe('parseDateCell', () => {
   it('normalises bare calendar dates without timezone drift', () => {
     expect(parseDateCell('2026-06-30', 'date')).toBe('2026-06-30');
+    expect(parseDateCell('2026/6/3', 'date')).toBe('2026-06-03');
   });
   it('emits full ISO for datetime', () => {
     expect(parseDateCell('2026-06-30', 'datetime')).toBe('2026-06-30T00:00:00.000Z');
@@ -99,16 +100,17 @@ describe('parseDateCell', () => {
 });
 
 /**
- * [#20534] A text cell is read only in ISO 8601 or the export's own
- * `YYYY-MM-DD HH:mm:ss`, on a calendar day that exists; everything else is
- * refused (`undefined`, so the row's `invalid_date`), never rolled over, never
+ * [#20534] A text cell is read only in ISO 8601, the export's own
+ * `YYYY-MM-DD HH:mm:ss` or a year-first date (`2026/7/15`, `2026/7/15 9:00`,
+ * by the maintainer ruling on the card), on a calendar day that exists;
+ * everything else is refused (`undefined`, so the row's `invalid_date`), never rolled over, never
  * read in the host's zone and never read month-first. A `date`'s year keeps
  * four digits. Every case runs under two host zones that disagree by twelve
  * hours, and must answer the same under both — the host-zone reading this
  * removes answered differently (`07/15/2026 10:00` was `…T14:00Z` in New York
  * and `…T02:00Z` in Shanghai).
  */
-describe('[#20534] parseDateCell — ISO 8601 or the export shape, on a real day', () => {
+describe('[#20534] parseDateCell — ISO 8601, the export shape or a year-first date, on a real day', () => {
   const HOST_ZONES = ['America/New_York', 'Asia/Shanghai'];
   const originalTz = process.env.TZ;
   afterEach(() => {
@@ -140,9 +142,12 @@ describe('[#20534] parseDateCell — ISO 8601 or the export shape, on a real day
     ['07/08/2026', 'datetime'], ['07/08/2026', 'date'],
     ['07/15/2026', 'date'], ['15 July 2026', 'date'], ['15 July 2026', 'datetime'],
     ['Jul 15 2026 10:00', 'time'], ['Wed, 15 Jul 2026 10:00:00 GMT', 'datetime'],
-    // Year-first but not ISO 8601.
-    ['2026/6/3', 'date'], ['2026/07/15', 'date'], ['2026-7-15', 'date'],
-    ['2026/08/01 06:00:00', 'datetime'], ['2026-07-15 9:00', 'datetime'],
+    // Year-first, outside its one form: an impossible day, a mixed separator,
+    // a clock out of range, a `T`, a zone, a fraction, a two-digit year.
+    ['2026/2/30', 'date'], ['2026/2/30', 'datetime'], ['2026/7-15', 'date'],
+    ['2026/7/15 24:00', 'datetime'], ['2026/7/15 9:60', 'datetime'],
+    ['2026/7/15T9:00', 'datetime'], ['2026/7/15 9:00Z', 'datetime'],
+    ['2026/7/15 9:00:00.5', 'datetime'], ['26/7/15', 'date'], ['07/15/2026', 'datetime'],
     // Reduced / expanded forms, a zone after a space, lower-case `t` / `z`.
     ['2026', 'date'], ['2026-07', 'datetime'], ['+002026-07-15', 'date'],
     ['2026-07-15 10:00Z', 'datetime'], ['2026-07-15 10:00:00+08:00', 'datetime'],
@@ -176,6 +181,19 @@ describe('[#20534] parseDateCell — ISO 8601 or the export shape, on a real day
     ['2026-07-15T24:00:00Z', 'datetime', '2026-07-16T00:00:00.000Z'],
     ['  2026-07-15  ', 'date', '2026-07-15'],
     ['10:00', 'time', '10:00:00'],
+    // A year-first date (Excel's zh-CN / ja-JP short date): the padded ISO day,
+    // and a clock read as a wall clock exactly as the export shape's is.
+    ['2026/6/3', 'date', '2026-06-03'],
+    ['2026/07/15', 'date', '2026-07-15'],
+    ['2026-7-15', 'date', '2026-07-15'],
+    ['2026/7/15', 'datetime', '2026-07-15T00:00:00.000Z'],
+    ['2026/7/15 9:00', 'datetime', '2026-07-15T09:00:00.000Z'],
+    ['2026/7/15 9:00', 'date', '2026-07-15'],
+    ['2026/7/15 9:00', 'time', '09:00:00'],
+    ['2026/08/01 06:00:00', 'datetime', '2026-08-01T06:00:00.000Z'],
+    ['2026-07-15 9:00', 'datetime', '2026-07-15T09:00:00.000Z'],
+    ['2028/2/29', 'date', '2028-02-29'],
+    ['0500/1/1', 'date', '0500-01-01'],
     // The year keeps four digits on every `date` branch.
     ['0500-01-01', 'date', '0500-01-01'],
     ['0001-01-01', 'date', '0001-01-01'],
@@ -234,7 +252,7 @@ describe('coerceRow', () => {
       note: { type: 'text' },
     });
     const { data, errors } = await coerceRow(
-      { done: '是', amount: '$1,200.50', priority: '高', tags: 'A, B', due: '2026-07-01', note: '  hi  ' },
+      { done: '是', amount: '$1,200.50', priority: '高', tags: 'A, B', due: '2026/07/01', note: '  hi  ' },
       metaMap,
       {},
     );
 
@@ -2,9 +2,10 @@
 
 /**
  * [#20534] `POST /api/v1/data/:object/import` reads a `date`, `datetime` or
- * `time` text cell only in ISO 8601 or the platform's own export shape
- * (`YYYY-MM-DD HH:mm:ss`), on a calendar day that exists, and pads a `date`'s
- * year to four digits — through the real route over a real `SqlDriver`
+ * `time` text cell only in ISO 8601, the platform's own export shape
+ * (`YYYY-MM-DD HH:mm:ss`) or a year-first date (`2026/7/15`, `2026/7/15 9:00`,
+ * by the maintainer ruling on the card), on a calendar day that exists, and
+ * pads a `date`'s year to four digits — through the real route over a real `SqlDriver`
  * (better-sqlite3 `:memory:`), under two host zones twelve hours apart.
  *
  * Measured through this route, JSON rows, `writeMode: 'insert'`, no business
@@ -24,6 +25,9 @@
  * | `2026-07-15 24:00` | datetime | `2026-07-16T04:00Z` · `2026-07-15T16:00Z` | row refused |
  * | `0500-01-01` / `0001-01-01` | date | row refused (`500-01-01` reached the write door) | `0500-01-01` / `0001-01-01` |
  * | `0001-01-01` | datetime | `1901-01-01T00:00:00.000Z` | `0001-01-01T00:00:00.000Z` |
+ * | `2026/7/15` | date | `2026-07-15` | unchanged |
+ * | `2026/7/15 9:00` | datetime | `2026-07-15T09:00:00.000Z` | unchanged |
+ * | `2026/2/30` | date | refused (`2026-02-30` reached the write door) | row refused by the reader |
  *
  * The `InMemoryDriver` column is this file's by construction, not by a second
  * arm: every cell is judged by the import's own reader (`parseDateCell`) before
@@ -69,6 +73,7 @@ const REFUSED: ReadonlyArray<readonly [field: Field, cell: string]> = [
   ['d', '15 July 2026'],
   ['t', '07/15/2026 10:00'],
   ['dt', '2026-07-15 24:00'],
+  ['d', '2026/2/30'],
 ];
 
 /** Admitted cells and what they store — the padding, the ISO control and the export shape. */
@@ -81,6 +86,9 @@ const ADMITTED: ReadonlyArray<readonly [field: Field, cell: string, stored: stri
   ['dt', '2026-07-15T10:00:00+08:00', '2026-07-15T02:00:00.000Z'],
   ['dt', '2026-07-15 10:00:00', '2026-07-15T10:00:00.000Z'],
   ['t', '10:00', '10:00:00'],
+  // A year-first date (Excel's zh-CN / ja-JP short date) stays admitted, padded.
+  ['d', '2026/7/15', '2026-07-15'],
+  ['dt', '2026/7/15 9:00', '2026-07-15T09:00:00.000Z'],
 ];
 
 function makeSqliteDriver() {
@@ -209,6 +217,17 @@ describe.each(HOST_ZONES)('[#20534] /import date cells, host TZ=$tz', ({ tz, jul
     }
   });
 
+  it('stores a year-first date-time as the same instant the export shape stores', async () => {
+    const res = await ctx.importRows({
+      format: 'json', writeMode: 'insert',
+      rows: [{ id: 'yf', dt: '2026/7/15 9:00' }, { id: 'ex', dt: '2026-07-15 09:00:00' }],
+    });
+    expect(res._json).toMatchObject({ total: 2, ok: 2, errors: 0, created: 2 });
+    const yearFirst = await stored(ctx.engine, 'yf', 'dt');
+    expect(yearFirst).toBe(await stored(ctx.engine, 'ex', 'dt'));
+    expect(yearFirst).toBe('2026-07-15T09:00:00.000Z');
+  });
+
   it('round-trips the export shape: an exported row re-imports as the same day and instant', async () => {
     await ctx.engine.insert(OBJECT, { id: 'src', d: '2026-07-15', dt: '2026-07-15T10:00:00.000Z', t: '10:00:00' });
     const exported = await ctx.exportCsv();
 
@@ -190,7 +190,7 @@ describe('import route — real engine + protocol integration', () => {
   it('coerces every special value type on insert (是→true, 高→high, name→id, date→ISO)', async () => {
     const csv = [
       'ID,标题,完成,优先级,分数,截止,负责人',
-      '1,写代码,是,高,"1,200",2026-06-30,张三',
+      '1,写代码,是,高,"1,200",2026/06/30,张三',
     ].join('\n');
     const res = await call(route, {
       format: 'csv', csv,
@@ -347,7 +347,7 @@ describe('import route — real engine + protocol integration', () => {
     const ws = wb.addWorksheet('Sheet1');
     ws.addRow(['ID', '标题', '完成', '优先级', '分数', '截止', '负责人']);
     ws.addRow(['1', '写代码', '是', '高', 1200, new Date('2026-06-30T00:00:00Z'), '张三']);
-    ws.addRow(['2', '测试', '否', '低', 3, '2026-07-01', '李四']);
+    ws.addRow(['2', '测试', '否', '低', 3, '2026/07/01', '李四']);
     const buf = await wb.xlsx.writeBuffer();
     const xlsxBase64 = Buffer.from(buf).toString('base64');
 
@@ -361,6 +361,8 @@ describe('import route — real engine + protocol integration', () => {
     expect(String(one.due)).toContain('2026-06-30');
     const two = await engine.findOne('task', { where: { id: '2' } });
     expect(two).toMatchObject({ title: '测试', done: false, priority: 'low', score: 3, owner: 'u2' });
+    // [#20534] A year-first text cell (Excel's zh-CN short date) is read as its ISO day.
+    expect(two.due).toBe('2026-07-01');
   });
 
   it('reads xlsxBase64 without an explicit format and honors the sheet selector', async () => {