intervalContainsZoned

Signature

intervalContainsZoned(intervalStart: string, intervalEnd: string, pointOrStart: string, pointEnd?: string): boolean

import { intervalContainsZoned } from "@northguild/gmt/zoned/interval";

Return true when pointOrStart falls within the interval [intervalStart, intervalEnd]

• (3-arg), or when the inner interval [innerStart, innerEnd] is fully contained within the outer interval [intervalStart, intervalEnd] (4-arg).
• Uses Temporal.Instant.compare for comparison (same instant semantics).
• Always-inclusive boundaries: start <= point <= end.
• Returns false if intervalStart > intervalEnd (invalid outer interval).
• Returns false if innerStart > innerEnd in 4-arg mode (invalid inner interval).
• Returns false on invalid input (wrong type, malformed strings, leap seconds).
• Accepts mixed calendar systems (E7’s D4-zoned, issue #152): both bare ISO zoned strings and GMT calendar-annotated ones ("5784-06-15T14:30:00-05:00[u-ca=hebrew][America/New_York]"), and the endpoints need not agree on a calendar. Ordering is calendar-independent — verified that Temporal.Instant carries no calendar field at all and that Instant.compare/ZonedDateTime.compare both return 0 for the same instant expressed in hebrew, islamic-civil, japanese and iso8601.
• Still rejects Temporal’s own [timeZone][u-ca=...] RFC 9557 ordering, which reads GMT’s calendar-native digits as ISO digits — see regex/calendar-zoned-date-time.ts.

Parameters

Parameter	Type	Description
intervalStart	string	ISO 8601 zoned datetime string for the outer interval start
intervalEnd	string	ISO 8601 zoned datetime string for the outer interval end
pointOrStart	string	ISO 8601 zoned datetime string for the point (3-arg) or inner start (4-arg)
pointEnd	string	optional ISO 8601 zoned datetime string for the inner interval end (4-arg mode)

Returns

true if the point or inner interval is contained, or false on invalid input

Examples

intervalContainsZoned("2024-01-01T00:00:00+00:00[UTC]", "2024-12-31T23:59:59+00:00[UTC]", "2024-06-15T12:00:00+00:00[UTC]") // true
intervalContainsZoned("2024-01-01T00:00:00+00:00[UTC]", "2024-12-31T23:59:59+00:00[UTC]", "2024-06-15T12:00:00+00:00[UTC]", "2024-07-15T12:00:00+00:00[UTC]") // true
intervalContainsZoned("2024-12-31T23:59:59+00:00[UTC]", "2024-01-01T00:00:00+00:00[UTC]", "2024-06-15T12:00:00+00:00[UTC]") // false
intervalContainsZoned("invalid", "2024-12-31T23:59:59+00:00[UTC]", "2024-06-15T12:00:00+00:00[UTC]") // false

Source

zoned/interval/intervalContainsZoned.ts