/**
 * Calculate elapsed time from the given start time (process.hrtime()).
 *
 * @param {[number, number]} timeStart
 * @param {(false | number)} fixed
 * @returns {(number | string)}
 */
export declare function getElapsedTime(timeStart: [number, number], fixed?: false | number): number;
/**
 * Gets a timestamp string for the given date.
 *
 * @param {Date} [date=new Date()]
 * @returns {string}
 */
export declare function getTimestampString(date?: Date): string;