@burglekitt/gmt/dist/zoned/interval/intervalFromDurationZoned.d.ts

Temporal-based date and time utilities with timezone support and polyfill integration

import type { Disambiguation, Offset, Overflow } from "../../types/index.js";
/**
 * Construct a zoned interval from a single point plus an ISO 8601 duration, anchored at either end.
 *
 * - `anchor: "start"` treats `value` as the interval start and adds `duration` to get the end.
 * - `anchor: "end"` treats `value` as the interval end and subtracts `duration` to get the start.
 * - Uses `Temporal.ZonedDateTime.prototype.add`/`.subtract`, so calendar units (years/months/weeks)
 *   resolve against `value` itself — no separate `relativeTo` is needed.
 * - `disambiguation` controls DST resolution ONLY when the arithmetic result lands on an ambiguous
 *   local time from a fall-back (DST-end) overlap: "compatible" (default), "earlier", "later", or
 *   "reject" (returns null). Mirrors `addZoned`'s exact semantics — has no effect on a spring-forward
 *   (DST-start) gap landing, which Temporal's arithmetic always resolves before disambiguation runs.
 * - `offset` is accepted for API consistency with `addZoned` but has **no effect here** for the same
 *   reason documented there: the disambiguation rebuild has no stored offset to prefer/use/ignore/reject.
 * - A negative `duration` (e.g. `"-P1D"`) can invert the computed span; returns null when that
 *   happens, mirroring `intervalIntersectionZoned`'s `start > end` rejection.
 * - `overflow` ("constrain" (default) | "reject") controls out-of-range results, e.g. adding 1 month
 *   to Jan 31: "constrain" clamps to Feb 29/28, "reject" returns null.
 * - Accepts a GMT calendar-annotated zoned string (as produced by `convertZonedToCalendar`) as
 *   well as a bare ISO one — E7 (issue #152). Calendar units in `duration` resolve against that
 *   calendar, and both returned endpoints are re-derived in it via `formatZonedInCalendar`. There
 *   is only ONE calendar-tagged input here, so no D5 pair policy applies — nothing can mismatch.
 * - Returns null on invalid input (unparseable `value`, invalid `duration`, or an `anchor` other
 *   than `"start"`/`"end"`).
 *
 * @param value ISO 8601 zoned datetime string, optionally calendar-annotated
 * @param duration ISO 8601 duration string
 * @param anchor "start" | "end" — which endpoint `value` represents
 * @param options optional: disambiguation ("compatible" | "earlier" | "later" | "reject"), offset ("prefer" | "use" | "ignore" | "reject" — accepted but inert, see above), overflow ("constrain" | "reject")
 * @returns `{ start, end }` with the constructed span, or null on invalid input
 *
 * @example intervalFromDurationZoned("2024-01-01T00:00:00+00:00[UTC]", "P1D", "start") // { start: "2024-01-01T00:00:00+00:00[UTC]", end: "2024-01-02T00:00:00+00:00[UTC]" }
 * @example intervalFromDurationZoned("2024-01-02T00:00:00+00:00[UTC]", "P1D", "end") // { start: "2024-01-01T00:00:00+00:00[UTC]", end: "2024-01-02T00:00:00+00:00[UTC]" }
 * @example intervalFromDurationZoned("2024-11-02T01:30:00-04:00[America/New_York]", "P1D", "start", { disambiguation: "later" }) // { start: "2024-11-02T01:30:00-04:00[America/New_York]", end: "2024-11-03T01:30:00-05:00[America/New_York]" } (fall-back overlap resolved; default "compatible" would return the -04:00 instant instead)
 * @example intervalFromDurationZoned("2024-01-31T12:00:00-05:00[America/New_York]", "P1M", "start", { overflow: "reject" }) // null
 * @example intervalFromDurationZoned("invalid", "P1D", "start") // null
 */
export declare function intervalFromDurationZoned(value: string, duration: string, anchor: "start" | "end", options?: {
    disambiguation?: Disambiguation;
    offset?: Offset;
    overflow?: Overflow;
}): {
    start: string;
    end: string;
} | null;