intervalEngulfsUtc

Signature

intervalEngulfsUtc(aStart: string, aEnd: string, bStart: string, bEnd: string): boolean

import { intervalEngulfsUtc } from "@northguild/gmt/utc/interval";

Return true when interval B is fully contained within interval A — every instant of B

• falls within A.
• Uses Temporal.Instant.compare for comparison.
• Equivalent to 4-argument intervalContainsUtc(aStart, aEnd, bStart, bEnd).
• Returns false if either interval is invalid (start > end).
• Returns false on invalid input (wrong type, malformed strings, leap seconds).

Parameters

Parameter	Type	Description
aStart	string	ISO 8601 UTC datetime string for the outer interval start
aEnd	string	ISO 8601 UTC datetime string for the outer interval end
bStart	string	ISO 8601 UTC datetime string for the inner interval start
bEnd	string	ISO 8601 UTC datetime string for the inner interval end

Returns

true if B is fully contained in A, or false on invalid input

Examples

intervalEngulfsUtc("2024-01-01T09:00:00Z", "2024-12-31T17:00:00Z", "2024-06-01T12:00:00Z", "2024-07-01T13:00:00Z") // true
intervalEngulfsUtc("2024-01-01T09:00:00Z", "2024-12-31T17:00:00Z", "2024-01-01T09:00:00Z", "2024-12-31T17:00:00Z") // true (equal intervals)
intervalEngulfsUtc("2024-01-01T09:00:00Z", "2024-12-31T17:00:00Z", "2024-01-01T09:00:00Z", "2024-06-30T12:00:00Z") // true
intervalEngulfsUtc("2024-06-01T12:00:00Z", "2024-07-01T13:00:00Z", "2024-01-01T09:00:00Z", "2024-12-31T17:00:00Z") // false
intervalEngulfsUtc("invalid", "2024-12-31T17:00:00Z", "2024-06-01T12:00:00Z", "2024-07-01T13:00:00Z") // false

Source

utc/interval/intervalEngulfsUtc.ts