/**
 * ISO 8601 date pattern.
 */
export declare const ISO_DATE_REGEX: RegExp;
/**
 * Get normalized Date object for the ISO formatted date strings.
 */
export declare function getNormalizedDate(dateString: string): Date;
/**
 * Converts a date string to a Date object.
 */
export declare function parseToLocalDate(value: unknown): Date | null;
/**
 * Checks if a string is a valid ISO 8601 date.
 */
export declare function isValidISODate(value: unknown): value is string;
/**
 * Time pattern: HH:mm, HH:mm:ss, or HH:mm:ss.SSS (24-hour).
 */
export declare const TIME_REGEX: RegExp;
/**
 * Parses a time string to a Date with that time on the Unix epoch.
 */
export declare function parseToLocalTime(value: unknown): Date | null;
/**
 * Checks if a string is a valid time in HH:mm, HH:mm:ss, or HH:mm:ss.SSS format.
 */
export declare function isValidTime(value: unknown): value is string;
/**
 * Returns a Date at local midnight for today.
 *
 * @returns {Date} A Date object representing today at local midnight.
 */
export declare function getTodayLocalDate(): Date;
/**
 * Returns a Date at local midnight offset by the given number of days from today.
 *
 * @param {number} days Number of days to offset from today. Positive values are in the future, negative in the past.
 * @returns {Date} A Date object at local midnight offset by the given days.
 */
export declare function getRelativeLocalDate(days: number): Date;
/**
 * Returns true if both Date objects fall on the same local calendar day.
 *
 * @param {Date} a The first date to compare.
 * @param {Date} b The second date to compare.
 * @returns {boolean} `true` if both dates are on the same local calendar day.
 */
export declare function isSameLocalDay(a: Date, b: Date): boolean;