import { Temporal } from "@js-temporal/polyfill";
/**
 * Duration parsing/formatting mode.
 * - "designator": Uses the standard Y/M/D designator format. Weeks are converted to days.
 * - "weeks": Uses the exclusive weeks format. Y/M/D units are ignored.
 */
export type DurationMode = "designator" | "weeks";
/**
 * Parses an ISO8601 duration string based on the specified mode.
 * - If the input is blank or invalid, returns zeros.
 * - In "weeks" mode, extracts only weeks.
 * - In "designator" mode, converts weeks to days and combines with Y/M/D.
 *
 * @param mode
 * @param iso
 * @returns The parsed parts.
 *
 * @example
 * parseByMode("designator", "P1Y2M3D") // => { years: 1, months: 2, days: 3, weeks: 0 }
 * parseByMode("designator", "P4W") // => { years: 0, months: 0, days: 28, weeks: 0 }
 * parseByMode("weeks", "P4W") // => { years: 0, months: 0, days: 0, weeks: 4 }
 * parseByMode("weeks", "P1Y2M3D") // => { years: 0, months: 0, days: 0, weeks: 0 }
 * parseByMode("designator", "") // => { years: 0, months: 0, days: 0, weeks: 0 }
 * parseByMode("weeks", null) // => { years: 0, months: 0, days: 0, weeks: 0 }
 */
export declare function parseByMode(mode: DurationMode, iso?: string | null): Temporal.DurationLike;
/**
 * Formats an ISO8601 duration string based on the specified mode and parts.
 * @param mode
 * @param parts
 */
export declare function formatByMode(mode: DurationMode, parts: Temporal.DurationLike): string;