/** How much of a name to render — the `Intl.DateTimeFormat` `month`/`weekday` widths. */
export type NameWidth = 'narrow' | 'short' | 'long';
/** The runtime's own locale, used whenever `locale` is omitted — matches what `toLocaleDateString()` would pick. */
export declare function resolveLocale(locale?: string): string;
/**
 * The twelve month names of `locale`, January first, at the requested width.
 *
 * @example
 * ```ts
 * getMonthNames('fr-FR')[0]; // 'janvier'
 * ```
 */
export declare function getMonthNames(locale?: string, width?: NameWidth): string[];
/**
 * The seven weekday names of `locale` at the requested width, rotated so index
 * `0` is `weekStartsOn` (`0` = Sunday … `6` = Saturday).
 *
 * @example
 * ```ts
 * getWeekDayNames('en-GB', 1, 'short'); // ['Mon', 'Tue', … 'Sun']
 * ```
 */
export declare function getWeekDayNames(locale?: string, weekStartsOn?: number, width?: NameWidth): string[];
/** The first day of the week `locale` uses (`0` = Sunday … `6` = Saturday), read from `Intl.Locale`'s week info, falling back to `0` on engines without it. */
export declare function getLocaleWeekStartsOn(locale?: string): 0 | 1 | 2 | 3 | 4 | 5 | 6;
/** The month heading label for `month` (e.g. `'janvier 2026'`), formatted for `locale`. */
export declare function formatMonthLabel(month: Date, locale?: string): string;
/** A bare year formatted for `locale` (e.g. `'2026'`, `'٢٠٢٦'` in `ar-EG`) using `Intl.NumberFormat` with grouping off, since a grouped `2,026` is not a year. */
export declare function formatYear(year: number, locale?: string): string;
/** A year page label (e.g. `'2020 – 2039'`), the year view's heading and grid name. */
export declare function formatYearRange(start: number, end: number, locale?: string): string;
/** A full, spoken-friendly date label (e.g. `'Monday, January 5, 2026'`) for live-region announcements. */
export declare function formatDateLabel(date: Date, locale?: string): string;
/** @internal Drops every memoized name list. */
export declare function clearLocaleNameCache(): void;