intervalOverlappingDaysUtc

Signature

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

Return how many distinct UTC calendar dates two UTC 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 instant 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 instant 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, leap seconds).

Parameters

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

Returns

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

Examples

import { intervalOverlappingDaysUtc } from "@northguild/gmt/utc/interval";

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

aStartaEndbStartbEnd

output

 

Source

utc/interval/intervalOverlappingDaysUtc.ts