deps/v8/src/js/i18n.js
function toLocaleDateTime(date, locales, options, required, defaults, service) {
  if (!(date instanceof GlobalDate)) {
    throw MakeTypeError(kMethodInvokedOnWrongType, "Date");
  }

  if (IsNaN(date)) return 'Invalid Date';

  var internalOptions = toDateTimeOptions(options, required, defaults);

  var dateFormat =
      cachedOrNewService(service, locales, options, internalOptions);

  return formatDate(dateFormat, date);
}
function toLocaleDateTime(date, locales, options, required, defaults, service) {
  if (!(date instanceof GlobalDate)) {
    throw MakeTypeError(kMethodInvokedOnWrongType, "Date");
  }

  if (IsNaN(date)) return 'Invalid Date';

  var internalOptions = toDateTimeOptions(options, required, defaults);

  var dateFormat =
      cachedOrNewService(service, locales, options, internalOptions);

  return formatDate(dateFormat, date);
}
Returns actual formatted date or fails if date parameter is invalid.