mergeIntervals

Signature

mergeIntervals(intervals: Interval[]): Interval[]

Collapse a list of half-open intervals into the fewest sorted, non-overlapping intervals.

• Overlapping and touching intervals (a.end is b.start) coalesce: [09, 12) ∪ [12, 17) is [09, 17). Intervals one nanosecond apart do not.
• Input order does not matter; the result is sorted by start, and no two results touch.
• Empty intervals (start === end) cover no time: one that touches or lies inside a run is absorbed, one that touches nothing is dropped (GMT rule).
• Endpoints are the caller’s own strings. A run keeps the start of its first interval (by instant, then input order) and the end of the first interval to reach its latest end (GMT rule: first wins ties between spellings of one instant).
• [] is both a legitimate result (an empty list, or a list of only empty intervals) and the invalid-input sentinel; check inputs with isValidInterval when the difference matters.
• The positional mergeIntervalsUtc, mergeIntervalsZoned (…) follow the same half-open rule and re-serialise endpoints instead of echoing the caller’s strings.
• Returns [] when intervals is not an array or any element is not a valid Interval.

Parameters

Parameter	Type	Description
intervals	Interval[]	array of { start, end } records of ISO 8601 instant strings

Returns

sorted, disjoint, non-touching { start, end } records, or [] on invalid input

Related types

• Interval

Examples

import { mergeIntervals } from "@northguild/gmt/interval/calculate";

mergeIntervals([{ start: "2024-01-01T13:00:00Z", end: "2024-01-01T17:00:00Z" }, { start: "2024-01-01T09:00:00Z", end: "2024-01-01T12:00:00Z" }]) // [{ start: "2024-01-01T09:00:00Z", end: "2024-01-01T12:00:00Z" }, { start: "2024-01-01T13:00:00Z", end: "2024-01-01T17:00:00Z" }]

intervals

×

×

+ add

output

 

Source

interval/calculate/mergeIntervals.ts