@burglekitt/gmt
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Temporal-based date and time utilities with timezone support and polyfill integration
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TypeScript
import type { Disambiguation, FractionalDigit, Offset } from "../../types/index.js";
/**
* Return the end of the week containing `value`, using `locale`'s first
* day of week (e.g. en-US: week ends Saturday, fr-FR: week ends Sunday).
*
* - Resolves the locale's first day of week via
* `Intl.Locale.prototype.weekInfo`, then resets the local time-of-day to
* the last instant of the day.
* - Falls back to Monday-start (so the week ends Sunday) if the runtime's
* `weekInfo` data doesn't resolve a first day for the locale.
* - `disambiguation` controls DST gap/overlap resolution when the
* end-of-day reset lands on an ambiguous local time: "compatible"
* (default, matches Temporal's default), "earlier", "later", or
* "reject" (throws, resulting in "").
* - `offset` controls whether the source's existing UTC offset is kept
* when resetting to end-of-day: "prefer" (Temporal's own default —
* keeps the source offset whenever still valid, which **makes
* `disambiguation` inert** for almost every case here), "use", "ignore"
* (**this function's default** — always recomputes from time zone +
* local time, discarding the stale offset; this is what makes
* `disambiguation` actually take effect), or "reject" (throws if the
* source offset is invalid for the new fields, independent of
* `disambiguation`). Leave `offset` at its default unless you
* specifically need Temporal's raw `.with()` semantics.
* - Distinct from `endOfZoned(value, "week", { weekStartsOn })`, which
* takes an explicit ISO-biased `weekStartsOn` option instead of deriving
* it from a locale.
* - Returns "" if `value` or `locale` is invalid.
*
* @param value zoned ISO 8601 datetime string
* @param locale BCP 47 locale tag (e.g. "en-US", "fr-FR")
* @param options optional: fractionalSecondDigits (number), disambiguation ("compatible" | "earlier" | "later" | "reject"), offset ("prefer" | "use" | "ignore" | "reject", default "ignore")
* @returns zoned ISO 8601 string for the end of `value`'s locale-relative week, or "" on invalid input
*
* @example getLocaleZonedEndOfWeek("2024-02-29T12:00:00+00:00[UTC]", "en-US") // "2024-03-02T23:59:59+00:00[UTC]" (Saturday)
* @example getLocaleZonedEndOfWeek("2024-02-29T12:00:00+00:00[UTC]", "fr-FR") // "2024-03-03T23:59:59+00:00[UTC]" (Sunday)
* @example getLocaleZonedEndOfWeek("invalid", "en-US") // ""
* @example getLocaleZonedEndOfWeek("2024-02-29T12:00:00+00:00[UTC]", "not-a-locale") // ""
*/
export declare function getLocaleZonedEndOfWeek(value: string, locale: string, optionsArg?: {
fractionalSecondDigits?: FractionalDigit;
disambiguation?: Disambiguation;
offset?: Offset;
}): string;