import { DateFormatter } from '../../shared/formatters/create-date-formatter.js';
/**
 * Formats the date time string or Date object.
 * If the date is invalid, it returns the original value.
 *
 * @param value - The date to format, as an ISO string or a Date
 * @param dateFormatter - The formatter to render the date with
 * @param dateFormat - The format to render, or undefined to return the value unformatted
 * @returns The formatted date, or the original value when it cannot be formatted
 */
export declare function formatDatetimeString(value: string | Date, dateFormatter: DateFormatter, dateFormat?: string): string;