mergeIntervalsDate

Signature

mergeIntervalsDate(intervals: { start: string; end: string; }[]): { start: string; end: string; }[]

Collapse a list of date intervals into the minimum set of non-overlapping intervals.

List-form generalization of intervalUnionDate, which is pairwise only.
Half-open: an interval holds every t with start <= t < end. Overlapping intervals and touching intervals (aEnd === bStart) join into one run; any gap, even one unit, keeps them apart (CORE-6’s mergeIntervals).
An empty interval (start === end) holds nothing: it is absorbed by a run it touches or lies in, and dropped otherwise, so every returned interval is non-empty.
Order of the input list does not matter; the result is sorted by start.
Returns [] for an empty list.
Returns [] when intervals is not an array, when any element is not a { start, end } record of valid ISO PlainDate strings, or when any element has start > end.
Accepts RFC 9557 calendar-annotated PlainDate strings — E5 (issue #78). Since the result is date values, every start/end across the whole list must carry the same calendar tag (or all be bare ISO); any mismatch returns [] (E5 decision of record D4).

Parameters

Parameter	Type	Description
`intervals`	`{ start: string; end: string; }[]`	array of `{ start, end }` records, optionally calendar-annotated

Returns

the minimum set of non-overlapping { start, end } records, sorted by start, or [] on invalid input / mismatched calendars

Members of each item

Member	Type	Description
`start`	`string`	The date the interval begins on, as an ISO 8601 date (`YYYY-MM-DD`). It keeps a calendar annotation such as `[u-ca=hebrew]` when the inputs carry one.
`end`	`string`	The first date after the interval, in the same format as `start`. It is exclusive: the interval holds everything from `start` up to but not including this value. It is always later than `start`.

Examples

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

mergeIntervalsDate([{ start: "2024-01-01", end: "2024-01-10" }, { start: "2024-01-05", end: "2024-01-15" }]) // [{ start: "2024-01-01", end: "2024-01-15" }]

Source

plain/interval/mergeIntervalsDate.ts