/**
 * Extracts the number of milliseconds since the Unix epoch that had passed when
 * the ULID was generated. If the ULID is malformed, an error will be thrown.
 *
 * @example Decode the time from a ULID
 * ```ts
 * import { decodeTime, ulid } from "mod.ts";
 * import { assertEquals } from "../assert/mod.ts";
 *
 * const timestamp = 150_000;
 * const ulidString = ulid(timestamp);
 *
 * assertEquals(decodeTime(ulidString), timestamp);
 * ```
 *
 * @param ulid The ULID to extract the timestamp from.
 * @returns The number of milliseconds since the Unix epoch that had passed when the ULID was generated.
 */
export declare function decodeTime(ulid: string): number;