import { Temporal } from "@js-temporal/polyfill";
import type { DateUnit } from "../../types/index.js";
/**
 * Round an ISO 8601 date string to the specified date unit.
 *
 * - Returns "" for invalid inputs.
 * - Accepts date units: "year", "month", "week", "day".
 * - Time units ("hour", "minute", etc.) are rejected and return "".
 * - All date units use manual start-of-unit rounding.
 * - Wraps all Temporal calls in try-catch; returns "" on any error.
 *
 * @param value ISO 8601 date string
 * @param options Rounding options: smallestUnit, optional roundingIncrement and roundingMode
 * @returns Rounded ISO 8601 date string, or "" on invalid input
 *
 * @example roundDate("2024-06-15", { smallestUnit: "year" }) // "2024-01-01"
 * @example roundDate("2024-06-15", { smallestUnit: "month" }) // "2024-07-01"
 * @example roundDate("2024-06-15", { smallestUnit: "week" }) // "2024-06-16"
 * @example roundDate("2024-06-15", { smallestUnit: "day" }) // "2024-06-15"
 * @example roundDate("invalid", { smallestUnit: "year" }) // ""
 */
export declare function roundDate(value: string, options: {
    smallestUnit: DateUnit;
    roundingIncrement?: number;
    roundingMode?: Temporal.RoundingMode;
}): string;