/**
 * Matches the datetime prefix shared by all files/directories belonging to a
 * single backup run.
 *
 * Examples:
 *   "20231215T142030.json"        → "20231215T142030"
 *   "20231215T142030Z.alias.vhd"  → "20231215T142030Z"
 *   "cache.json.gz"               → undefined  (not a backup file)
 */
export declare const DATETIME_RE: RegExp;
export declare function extractDatetime(filename: string): string | undefined;
export declare function parseDatetime(datetime: string): number | undefined;