intervalAbutsDate

Signature

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

Return true when two half-open date intervals [aStart, aEnd) and [bStart, bEnd) are exactly adjacent — one ends where the other starts, so they share nothing and leave no gap.

• Half-open: an interval holds every t with start <= t < end, so an interval’s end is the first value after it. Returns true when aEnd === bStart or bEnd === aStart (Allen’s “meets”). There is no one-day step: a one-day gap is a gap.
• An empty interval (start === end) abuts nothing.
• Uses Temporal.PlainDate.compare for comparison.
• Returns false when intervals overlap, are disjoint with a gap, or are invalid.
• Returns false on invalid input (wrong type, malformed strings).
• Accepts RFC 9557 calendar-annotated PlainDate strings (as produced by convertDateToCalendar) — E5 (issue #78). Comparison is by calendar-independent ordering (Temporal.PlainDate.compare ignores calendar), so the four endpoints may carry different or no calendar tags — E5 decision of record D4 (ordering-only functions accept mixed calendars).
• Compatibility: since 1.16.0 calendar strings are RFC 9557 (ISO digits, [u-ca=<id>], canonical calendar ids); see isValidCalendarDate.

Parameters

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

Returns

true if intervals are exactly adjacent, or false on invalid input

Examples

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

intervalAbutsDate("2024-01-01", "2024-06-30", "2024-06-30", "2024-12-31") // true

aStartaEndbStartbEnd

output

 

Source

plain/interval/intervalAbutsDate.ts