larksuite/cli · error

date expects an ISO yyyy-mm-dd string, got %s

Error message

date expects an ISO yyyy-mm-dd string, got %s

What it means

A column declared "date" must carry an ISO yyyy-mm-dd string because buildTypedCell parses it into an Excel serial for the sheet. A non-string JSON value (number, bool, object, null) fails this type check; the caller adds row/column context and wraps it in a typed validation error.

Source

Thrown at shortcuts/sheets/lark_sheet_table_io.go:704

		cell["value"] = raw
	case "string":
		cell["value"] = stringifyCellValue(raw)
	case "number":
		n, ok := raw.(json.Number)
		if !ok {
			return nil, fmt.Errorf("number expects a numeric value, got %s", describeJSONType(raw)) //nolint:forbidigo // intermediate error; callers wrap it into a typed --sheets/--values validation error with row/column context
		}
		cell["value"] = n
	case "bool":
		b, ok := raw.(bool)
		if !ok {
			return nil, fmt.Errorf("bool expects true/false, got %s", describeJSONType(raw)) //nolint:forbidigo // intermediate error; callers wrap it into a typed --sheets/--values validation error with row/column context
		}
		cell["value"] = b
	case "date":
		str, ok := raw.(string)
		if !ok {
			return nil, fmt.Errorf("date expects an ISO yyyy-mm-dd string, got %s", describeJSONType(raw)) //nolint:forbidigo // intermediate error; callers wrap it into a typed --sheets/--values validation error with row/column context
		}
		serial, err := isoDateToSerial(str)
		if err != nil {
			return nil, err
		}
		cell["value"] = serial
	default:
		return nil, fmt.Errorf("unsupported type %q", col.Type) //nolint:forbidigo // intermediate error; callers wrap it into a typed --sheets/--values validation error with row/column context
	}
	return cell, nil
}

// stringifyCellValue renders any JSON scalar as the literal text a string
// column should hold. json.Number keeps its exact digits (no scientific
// notation), so IDs / postcodes survive as written.
func stringifyCellValue(raw interface{}) string {
	switch v := raw.(type) {
	case string:

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Convert values to "yyyy-mm-dd" strings, e.g. "2026-01-31" (ISO datetime strings like 2026-01-31T09:00:00Z are also accepted)
2. If values are raw numbers/text, change the column dtype to "number" or "object"
3. Replace null/empty cells with real dates or drop those rows

Example fix

// before
{"name":"Due","type":"date","data":[1738368000]}
// after
{"name":"Due","type":"date","data":["2026-01-31"]}

function assertDateColumn(col) {
  col.data.forEach((v, i) => {
    if (typeof v !== 'string' || !/^\d{4}-\d{2}-\d{2}(T[0-9:.+Z-]+)?$/.test(v))
      throw new Error(`column ${col.name} (date): row ${i} value ${JSON.stringify(v)} is not an ISO date string`);
  });
}

function isISODateString(v) { return typeof v === 'string' && /^\d{4}-\d{2}-\d{2}(T[0-9:.+Z-]+)?$/.test(v); }

try {
  await run(['lark','sheet','table-put','--sheets',payload]);
} catch (e) {
  if (/date expects an ISO yyyy-mm-dd string/.test(e.message)) {
    // convert epoch numbers/Date objects to 'yyyy-mm-dd' strings and retry
  }
  throw e;
}

When it happens

Trigger: Date column given epoch numbers, JSON null for empty cells, or already-serialized date objects instead of "2026-01-31" strings.

Common situations: Feeding JS Date or epoch millis directly into the payload; null gaps in a date column; converters emitting numbers for dates.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• number expects a numeric value, got %s
• bool expects true/false, got %s
• date column has an empty cell — drop the empty rows, fill re
• %s must be a boolean
• %s must be an integer

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/972f76e534bd7e32. Report an issue: GitHub.