/**
 * Formats a local Date as an ISO date string (`YYYY-MM-DD`).
 * Returns an empty string when the date is missing or invalid.
 */
export declare const formatDateToString: (date: Date | undefined) => string;
/**
 * Parses an ISO date string (`YYYY-MM-DD`) into a local Date.
 * Returns `undefined` when the value is empty or does not represent a valid date.
 */
export declare const parseStringToDate: (value: string) => Date | undefined;