import type { SelectOption } from "./select";
/** `displayHour` is the locale's: under a 12-hour clock only `pm` distinguishes two times. */
export interface TimeParts {
    displayHour: number;
    minute: number;
    /** `null` in a 24-hour locale. */
    pm: boolean | null;
}
export declare function dayPeriodLabels(locale: string): {
    am: string;
    pm: string;
} | null;
/** `null` when not a canonical `"HH:mm"`. */
export declare function timeToMinuteOfDay(value: string): number | null;
/** Total: an unreadable value decomposes to midnight, since the columns always need a row. */
export declare function decomposeTime(value: string, locale: string): TimeParts;
export declare function composeTime(parts: TimeParts): string;
/** Under {@link TIME_FORMAT_OPTIONS}, as the date field's segments; a non-time comes back unchanged rather
 *  than "Invalid Date". */
export declare function formatTimeOfDay(value: string, locale: string): string;
/** A 12-hour locale leads with 12, or midnight and noon sit at the bottom. */
export declare function hourOptions(locale: string): SelectOption<string>[];
/** Every minute: a step would make a cut-off at 13:07 unreachable. */
export declare function minuteOptions(): SelectOption<string>[];
/** Empty where the locale has none. */
export declare function dayPeriodOptions(locale: string): SelectOption<string>[];