dayjs vs moment vs luxon vs js-joda | JavaScript Date and Time Manipulation Libraries

Package	Downloads	Stars	Size	Issues	Publish	License

dayjs	30,531,851	48,384	679 kB	1,164	17 days ago	MIT
moment	25,800,382	48,090	4.35 MB	303	2 years ago	MIT
luxon	17,050,418	16,230	4.59 MB	181	2 months ago	MIT
js-joda	33,550	1,652	-	21	6 years ago	BSD-3-Clause

Package

Downloads

Stars

Size

Issues

Publish

License

dayjs

30,531,851

48,384

679 kB

1,164

17 days ago

MIT

moment

25,800,382

48,090

4.35 MB

303

2 years ago

MIT

luxon

17,050,418

16,230

4.59 MB

181

2 months ago

MIT

js-joda

33,550

1,652

6 years ago

BSD-3-Clause

API Design & Mutability

dayjs:
dayjs uses an immutable API with a fluent chainable syntax similar to Moment.js, making it intuitive for developers familiar with Moment while avoiding unintended side effects.
moment:
moment uses a mutable API, which can lead to unexpected side effects. While its chainable syntax is familiar, mutability is considered a design flaw in modern date libraries.
luxon:
luxon is fully immutable and leverages a modern, functional style. Its API is clean but differs significantly from Moment, requiring a learning curve for developers accustomed to older libraries.
js-joda:
js-joda provides a strictly immutable API with a rich object model (e.g., LocalDate, ZonedDateTime), inspired by Java’s modern time API, ensuring thread safety and predictable behavior.

Bundle Size

dayjs:
dayjs is extremely lightweight (~2 KB minified + gzipped). Additional features like timezones or locales are available as plugins, keeping the core minimal.
moment:
moment is large (~65 KB minified + gzipped) and includes all locales by default, making it unsuitable for performance-sensitive applications.
luxon:
luxon is around ~10–15 KB gzipped and has no dependencies. It relies on the browser’s Intl API, so polyfills may be needed in older environments.
js-joda:
js-joda is moderately sized (~40 KB gzipped) due to its comprehensive API surface and Java-like architecture, which may be heavier than needed for simple use cases.

Timezone Support

dayjs:
dayjs supports timezones via an optional plugin (timezone), requiring manual inclusion of timezone data (e.g., from Intl or custom offsets).
moment:
moment supports timezones via the separate moment-timezone package, which bundles large timezone data and increases application size substantially.
luxon:
luxon has excellent built-in timezone support using the browser’s Intl API, including named timezones (e.g., 'America/New_York') without extra packages.
js-joda:
js-joda supports timezones through its @js-joda/timezone package, which includes IANA timezone data. This adds significant size but enables full timezone-aware operations.

Internationalization (i18n)

dayjs:
dayjs supports i18n through locale plugins. Only the required locales need to be imported, keeping bundle size efficient.
moment:
moment includes all locales by default unless manually tree-shaken, leading to bloat. Locale switching is supported but adds maintenance overhead.
luxon:
luxon leverages the browser’s Intl API for formatting in any locale supported by the user’s environment—no extra locale files needed.
js-joda:
js-joda requires additional packages like @js-joda/locale for i18n formatting, which adds complexity and size.

Code Examples

dayjs:

dayjs example for parsing and formatting

const dayjs = require('dayjs');
const date = dayjs('2025-11-04');
console.log(date.format('YYYY-MM-DD')); // '2025-11-04'

moment:

moment example (legacy)

const moment = require('moment');
const date = moment('2025-11-04');
console.log(date.format('YYYY-MM-DD')); // '2025-11-04'

luxon:

luxon example for timezone-aware formatting

const { DateTime } = require('luxon');
const dt = DateTime.fromISO('2025-11-04T12:00:00', { zone: 'America/New_York' });
console.log(dt.toFormat('yyyy-MM-dd HH:mm ZZZZ'));

js-joda:

js-joda example for creating a date and adding days

const { LocalDate } = require('@js-joda/core');
const date = LocalDate.parse('2025-11-04');
const future = date.plusDays(7);
console.log(future.toString()); // '2025-11-11'

Getting Started

Documentation

You can find more details, API, and other docs on day.js.org website.

Installation

npm install dayjs --save

API

It's easy to use Day.js APIs to parse, validate, manipulate, and display dates and times.

dayjs('2018-08-08') // parse dayjs().format('{YYYY} MM-DDTHH:mm:ss SSS [Z] A') // display dayjs().set('month', 3).month() // get & set dayjs().add(1, 'year') // manipulate dayjs().isBefore(dayjs()) // query

I18n

Day.js has great support for internationalization.

But none of them will be included in your build unless you use it.

import 'dayjs/locale/es' // load on demand dayjs.locale('es') // use Spanish locale globally dayjs('2018-05-05').locale('zh-cn').format() // use Chinese Simplified locale in a specific instance

Plugin

A plugin is an independent module that can be added to Day.js to extend functionality or add new features.

import advancedFormat from 'dayjs/plugin/advancedFormat' // load on demand dayjs.extend(advancedFormat) // use plugin dayjs().format('Q Do k kk X x') // more available formats