toMillis

Converts a date to a timestamp in milliseconds (epoch millis).

Use this when you need a plain number from a DateLike value (e.g. for Date.now() comparisons, localStorage, or JS-native APIs).

Available since v2.0.0

Import

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

toMillis(date: DateLike): number | null

Parameter	Type	Description
`date`	`DateLike`	The date to convert

number | null — Milliseconds since the Unix epoch, or null for invalid input

toMillis('2025-01-19T12:00:00Z') // => 1737288000000
toMillis(null)                    // => null

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)
Temporal.Instant | Temporal.ZonedDateTime — read via their epochMilliseconds property

type DateLike = Date | number | string | Temporal.Instant | Temporal.ZonedDateTime