import type { Ref } from '@stacksjs/stx';
/**
 * Reactive date formatting composable.
 * Returns a ref containing the formatted date string.
 * Uses @stacksjs/datetime format() under the hood.
 *
 * @param date - Date value (or ref) to format
 * @param formatStr - Token-based format string (e.g. 'YYYY-MM-DD HH:mm:ss')
 */
export declare function useDateFormat(date: Ref<Date | string | number> | Date | string | number, formatStr: string): Ref<string>;