/** Generate range of given lengths using given function. */
export declare function range<T>(length: number, mapFn: (index: number) => T): T[];
/** Adds 0 if number is less then 10 */
export declare function _leftPad(n: number): string;
/** Converts date to ISO8601 */
export declare function toIso8601(fdDate: {
    year: number;
    month: number;
    day: number;
    hour: number;
    minute: number;
    second: number;
}): string;
/**
 * @param params e.g. { year: 2020, month: 1, day: 1, hour: 0, minute: 0, second: 0 }
 */
export declare function isValidByParams(params: {
    year: number;
    month: number;
    day?: number;
    hour?: number;
    minute?: number;
    second?: number;
}): boolean;
