intervalIntersectionTime

Signature

intervalIntersectionTime(aStart: string, aEnd: string, bStart: string, bEnd: string): { start: string; end: string; }

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

Return the overlapping span of two time intervals, or null when they do not overlap.

• Uses Temporal.PlainTime.compare for comparison.
• Adjacent intervals (e.g. aEnd === bStart) share one instant and DO overlap.
• Returns null if either interval is invalid (start > end).
• Returns null on invalid input (wrong type, malformed strings).

Parameters

Parameter	Type	Description
aStart	string	ISO 8601 time string for the first interval start
aEnd	string	ISO 8601 time string for the first interval end
bStart	string	ISO 8601 time string for the second interval start
bEnd	string	ISO 8601 time string for the second interval end

Returns

{ start, end } with the overlapping span, or null on invalid input / no overlap

Examples

intervalIntersectionTime("09:00:00", "17:00:00", "12:00:00", "18:00:00") // { start: "12:00:00", end: "17:00:00" }
intervalIntersectionTime("09:00:00", "17:00:00", "17:00:00", "18:00:00") // { start: "17:00:00", end: "17:00:00" }
intervalIntersectionTime("09:00:00", "17:00:00", "18:00:00", "20:00:00") // null
intervalIntersectionTime("09:00:00", "17:00:00", "10:00:00", "11:00:00") // { start: "10:00:00", end: "11:00:00" }
intervalIntersectionTime("invalid", "17:00:00", "12:00:00", "18:00:00") // null

Source

plain/interval/intervalIntersectionTime.ts