import type { Locale } from "date-fns";
import type { AppLocale, AppTimeFormat, AppDateFormat } from "../../app/types.js";
export type DatetimeContext = {
    locale: AppLocale;
    dateFnsLocale: Locale;
    timezone: string;
    timeFormat: AppTimeFormat;
    dateFormat: AppDateFormat;
};
/** Sync module-level datetime prefs from AppProvider (mirrors syncI18nLocale). */
export declare function syncDatetimeContext(partial: Pick<DatetimeContext, "locale" | "timezone" | "timeFormat" | "dateFormat"> & {
    dateFnsLocale?: Locale;
}): void;
export declare function getDatetimeContext(): Readonly<DatetimeContext>;
export declare function enableLiveRelativeFormatting(): void;
export declare function disableLiveRelativeFormatting(): void;
export declare function canUseLiveRelativeFormatting(): boolean;
/** Vitest only — reset to defaults between cases. */
export declare function resetDatetimeContextForTests(): void;