vremel/src/datetime/isWithinInterval.ts

JavaScript date utility library for Temporal API

import { assertSameType, assertValidInterval } from "../assert.js";
import type { Interval, Temporal } from "../types.js";
import { compare } from "./_compare.js";

/**
 * Checks whether the given datetime is within the interval.
 * @param dateTime temporal object
 * @param interval interval
 * @returns Whether the given datetime is within the interval
 */
export function isWithinInterval<
	DateTime extends
		| Temporal.Instant
		| Temporal.ZonedDateTime
		| Temporal.PlainDate
		| Temporal.PlainTime
		| Temporal.PlainDateTime
		| Temporal.PlainYearMonth,
>(dateTime: DateTime, interval: Interval<DateTime>): boolean {
	assertValidInterval(interval);
	assertSameType(dateTime, interval.start);
	return (
		compare(dateTime, interval.start) !== -1 &&
		compare(dateTime, interval.end) !== 1
	);
}