Function parseDate

src/date_utils.ts:296–336

(
  value: string,
  dateFormat: string | string[],
  locale: Locale | undefined,
  strictParsing: boolean,
  refDate: Date = newDate(),
)

 * @returns - The parsed date or null.
 */
export function parseDate(
  value: string,
  dateFormat: string | string[],
  locale: Locale | undefined,
  strictParsing: boolean,
  refDate: Date = newDate(),
): Date | null {
  const localeObject =
    getLocaleObject(locale) || getLocaleObject(getDefaultLocale());

  const formats = Array.isArray(dateFormat) ? dateFormat : [dateFormat];

  for (const format of formats) {
    const parsedDate = parse(value, format, refDate, {
      locale: localeObject,
      useAdditionalWeekYearTokens: true,
      useAdditionalDayOfYearTokens: true,
    });
    if (
      isValid(parsedDate) &&
      (!strictParsing || value === formatDate(parsedDate, format, locale))
    ) {
      return parsedDate;
    }
  }

  // When strictParsing is false, try native Date parsing as a fallback
  // This allows flexible input formats like "12/05/2025" or "2025-12-16"
  // even when the dateFormat prop specifies a different format.
  // Only attempt this for inputs that look like complete dates (minimum
  // length of 8 characters, e.g., "1/1/2000") to avoid parsing partial
  // inputs like "03/" or "2000" which should be handled by parseDateForNavigation.
  if (!strictParsing && value && value.length >= 8) {
    const nativeDate = new Date(value);
    if (isValidDate(nativeDate)) {
      return nativeDate;
    }
  }

  return null;
}

/**
 * Parses a partial date string for calendar navigation purposes.