/**
 * Normalizes a locale string to a valid format.
 * Keeps letter-based region codes (e.g., 'en-GB', 'es-ES') but strips
 * numeric UN M.49 region codes (e.g., 'es-419' -> 'es').
 * Handles both dash and underscore separators.
 * @example
 * normalizeLocale('en-GB') // 'en-GB' (letter region preserved)
 * normalizeLocale('es-419') // 'es' (numeric region stripped)
 * normalizeLocale('zh-Hans-CN') // 'zh-CN' (script stripped, letter region preserved)
 * normalizeLocale('en_US') // 'en-US' (underscore normalized)
 */
export declare function normalizeLocale(locale?: string): string;
/**
 * Gets the country code from a time zone string.
 * @param timeZone - IANA time zone string (e.g., 'Europe/Madrid')
 * @returns ISO 3166-1 alpha-2 country code (e.g., 'ES') or undefined if not found
 * @example
 * getCountryFromTimeZone('Europe/Madrid') // 'ES'
 * getCountryFromTimeZone('America/New_York') // 'US'
 */
export declare function getCountryFromTimeZone(timeZone?: string): string | undefined;
/**
 * Mapping of IANA time zones to ISO 3166-1 alpha-2 country codes.
 * Used to infer a user's country from their browser's time zone.
 */
export declare const timeZoneToCountryCode: Record<string, string>;