isWithinRange

Checks whether a date falls within a range (inclusive on both ends).

Returns false if any of the inputs is invalid.

Available since v2.0.0

Import

import { isWithinRange } from '@helpers4/date';

Signature

isWithinRange(date: DateLike, start: DateLike, end: DateLike): boolean

Parameters

Parameter	Type	Description
date	DateLike	The date to check
start	DateLike	Start of the range (inclusive)
end	DateLike	End of the range (inclusive)

Returns

boolean — true if start <= date <= end

Examples

isWithinRange

isWithinRange('2025-06-15', '2025-01-01', '2025-12-31') // => true
isWithinRange('2024-06-15', '2025-01-01', '2025-12-31') // => false

Related Types

DateRange

A date range represented as a pair of date-like values.

interface DateRange {
  end: DateLike;
  start: DateLike;
}

DateLike

A value that can be converted to a Date.

• Date — used as-is (validated for Invalid Date)
• number — treated as a timestamp (seconds or milliseconds, auto-detected); 0 is treated as invalid and produces null in ensureDate
• string — parsed via new Date(string)
• EpochMilliseconds — any object with a epochMilliseconds property (e.g. Temporal.Instant, Temporal.ZonedDateTime)

// TODO: When the Temporal API reaches Stage 4 and is available without // flags in all major runtimes, consider narrowing the union to the // concrete Temporal types for stricter type-checking.

type DateLike = Date | number | string | EpochMilliseconds

EpochMilliseconds

An object that exposes an epoch timestamp in milliseconds.

This structural type is satisfied by Temporal.Instant and Temporal.ZonedDateTime (and any future object that carries the same property), so callers can pass Temporal values without importing them.

interface EpochMilliseconds {
  epochMilliseconds: number;
}

Source

View source on GitHub