import type { CustomOptions, CustomValidate } from "../custom/index.ts";
/**
 * Determines if the input is a date.
 *
 * @param input The value to check.
 * @param validate Additional validation to run against the input if it is a date. Default is `undefined`.
 * @returns `true` if the input is a date, `false` otherwise.
 */
export declare function isDate(input: unknown, validate?: CustomValidate<Date>): input is Date;
export type DateOptions = Omit<CustomOptions<Date>, "typecheck">;
/**
 * Verifies that the input is a date, and returns it.
 * If the input is not a date, the fallback value is returned.
 *
 * @param input The value to check.
 * @param fallback The value to return if the input is not a date. Default is `null`.
 * @returns The date value of the input, or the fallback if the input is not a date.
 */
export declare function date(input: unknown, fallback: Date, options?: DateOptions): Date;
export declare function date(input: unknown, fallback?: Date | null | undefined, options?: DateOptions): Date | null;
export declare function toDate(input: unknown): Date | null;