IntlApiLocaleFormatting [rule] v1.0.0

Dates, times, numbers, currencies, and list conjunctions must be formatted using the JavaScript Intl API (Intl.DateTimeFormat, Intl.NumberFormat, Intl.ListFormat) rather than hard-coded locale-specific strings.

Applies To

@community/type-html-artifact

Severity

warning

Exceptions

• • Case: ISO 8601 machine-readable dates in attributes
  • Allowed When: datetime attributes always use ISO 8601 (YYYY-MM-DD); only the visible text needs Intl formatting.

IntlApiLocaleFormatting [rule] v1.0.0

Dates, times, numbers, currencies, and list conjunctions must be formatted using the JavaScript Intl API (Intl.DateTimeFormat, Intl.NumberFormat, Intl.ListFormat) rather than hard-coded locale-specific strings.

Applies To

@community/type-html-artifact

Severity

warning

Exceptions

• • Case: ISO 8601 machine-readable dates in attributes
  • Allowed When: datetime attributes always use ISO 8601 (YYYY-MM-DD); only the visible text needs Intl formatting.

Rationale

Hard-coded formats like '1,234.56' or 'Jan 5, 2026' are incorrect in many locales: German uses '1.234,56', many countries write dates as day-first. The Intl API handles these differences automatically and is available in all modern browsers.

Applies To

@community/type-html-artifact

Severity

warning

Exceptions

• • Case: ISO 8601 machine-readable dates in attributes
  • Allowed When: datetime attributes always use ISO 8601 (YYYY-MM-DD); only the visible text needs Intl formatting.