interface IsValidDateRangeProps {
    value1: string;
    value2: string;
    options?: {
        allowEqual?: boolean;
    };
}
/**
 * Return whether `value1` is before `value2`.
 *
 * - Validates both dates using regex and Temporal.PlainDate.from().
 * - Rejects leap seconds in either date.
 * - When `options.allowEqual` is true, equality is considered valid as well.
 *
 * @param value1 first ISO PlainDate string
 * @param value2 second ISO PlainDate string
 * @param options optional allowEqual flag
 * @returns boolean indicating whether the date range is valid
 *
 * @example isValidDateRange({ value1: "2024-02-28", value2: "2024-02-29" }) // true
 * @example isValidDateRange({ value1: "2024-02-29", value2: "2024-02-28" }) // false
 * @example isValidDateRange({ value1: "2024-02-29", value2: "2024-02-29" }) // false
 * @example isValidDateRange({ value1: "2024-02-29", value2: "2024-02-29", options: { allowEqual: true } }) // true
 */
export declare function isValidDateRange({ value1, value2, options, }: IsValidDateRangeProps): boolean;
export {};