intervalOverlappingDaysDateTime

Signature

intervalOverlappingDaysDateTime(aStart: string, aEnd: string, bStart: string, bEnd: string): number | null

Return how many distinct calendar dates two datetime intervals share.

• Half-open: an interval holds every t with start <= t < end. The count is the number of calendar days holding at least one moment of the intersection [max(aStart, bStart), min(aEnd, bEnd)). An intersection ending exactly at midnight does not reach that day.
• Touching intervals (aEnd === bStart) share no moment and count 0; so does an empty interval.
• Returns 0 when the intervals share nothing (a well-defined answer, not invalid input).
• 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 datetime string for the first interval start
aEnd	string	ISO 8601 datetime string for the first interval end
bStart	string	ISO 8601 datetime string for the second interval start
bEnd	string	ISO 8601 datetime string for the second interval end

Returns

number of shared calendar dates, 0 when disjoint, or null on invalid input

Examples

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

intervalOverlappingDaysDateTime("2024-01-01T23:59:00", "2024-01-02T00:01:00", "2024-01-01T23:59:00", "2024-01-02T00:01:00") // 2

aStartaEndbStartbEnd

output

 

Source

plain/interval/intervalOverlappingDaysDateTime.ts