intervalsOverlapDate

Signature

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

Return true when the half-open date intervals [aStart, aEnd) and [bStart, bEnd) share at least one day.

• Half-open: an interval holds every date d with start <= d < end, so end itself is not in it (the rule CORE-6’s intervalsOverlap uses). The test is aStart < bEnd && bStart < aEnd.
• Touching intervals (aEnd equal to bStart) share no day and do not overlap.
• An empty interval (start === end) overlaps only an interval it lies strictly inside.
• Uses Temporal.PlainDate.compare for comparison.
• Returns false if either interval is invalid (start > end).
• Returns false on invalid input (wrong type, malformed strings).
• Accepts RFC 9557 calendar-annotated PlainDate strings — E5 (issue #78). Ordering is calendar-independent, so arguments may carry different or no calendar tags (D4).
• 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 (excluded), 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 (excluded), optionally calendar-annotated

Returns

true if intervals overlap, or false on invalid input

Examples

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

intervalsOverlapDate("2024-01-01", "2024-06-30", "2024-04-01", "2024-12-31") // true

aStartaEndbStartbEnd

output

 

Source

plain/interval/intervalsOverlapDate.ts