/**
 * Parses a date string and returns a human-readable format.
 * If the input is invalid, it returns the original string or a placeholder.
 *
 * @param dateStr - The date string to parse.
 * @returns A human-readable date string or the original input if invalid.
 */
export declare function formatHumanReadableDate(dateStr?: string): string;
export declare function formatUptime(ms: number): string;