intervalEngulfsDate

Signature

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

import { intervalEngulfsDate } from "@northguild/gmt/plain/interval";

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

• falls within A.
• Uses Temporal.PlainDate.compare for comparison.
• Equivalent to 4-argument intervalContainsDate(aStart, aEnd, bStart, bEnd).
• Returns false if either interval is invalid (start > end).
• Returns false on invalid input (wrong type, malformed strings).
• Accepts GMT calendar-annotated PlainDate strings — E5 (issue #78). Ordering is calendar-independent, so arguments may carry different or no calendar tags (D4).

Parameters

Parameter	Type	Description
aStart	string	ISO 8601 date string for the outer interval start, optionally calendar-annotated
aEnd	string	ISO 8601 date string for the outer interval end, optionally calendar-annotated
bStart	string	ISO 8601 date string for the inner interval start, optionally calendar-annotated
bEnd	string	ISO 8601 date string for the inner interval end, optionally calendar-annotated

Returns

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

Examples

intervalEngulfsDate("2024-01-01", "2024-12-31", "2024-06-01", "2024-07-01") // true
intervalEngulfsDate("2024-01-01", "2024-12-31", "2024-01-01", "2024-12-31") // true (equal intervals)
intervalEngulfsDate("2024-01-01", "2024-12-31", "2024-06-01", "2024-12-31") // true
intervalEngulfsDate("2024-06-01", "2024-07-01", "2024-01-01", "2024-12-31") // false
intervalEngulfsDate("invalid", "2024-12-31", "2024-06-01", "2024-07-01") // false

Source

plain/interval/intervalEngulfsDate.ts