Dayjs
⏰ Day.js 2kB immutable date-time library alternative to Moment.js with the same modern API
English | [简体中文](./docs/zh-cn/README.zh-CN.md) | [日本語](./docs/ja/README-ja.md) | [Português Brasileiro](./docs/pt-br/README-pt-br.md) | [한국어](./docs/ko/README-ko.md) | [Español (España)](./docs/es-es/README-es-es.md) | [Русский](./docs/ru/README-ru.md) | [Türkçe](./docs/tr/README-tr.md) | [සිංහල](./docs/si/README-si.md) | [עברית](./docs/he/README-he.md) The project is written primarily in JavaScript, distributed under the MIT License license, first published in 2018. It has gained significant community traction with 48,662 stars and 2,449 forks on GitHub. Key topics include: date, date-formatting, datetime, dayjs, moment.
English | 简体中文 | 日本語 | Português Brasileiro | 한국어 | Español (España) | Русский | Türkçe | සිංහල | עברית
<p align="center"><a href="https://day.js.org/" target="_blank" rel="noopener noreferrer"><img width="550" src="https://user-images.githubusercontent.com/17680888/39081119-3057bbe2-456e-11e8-862c-646133ad4b43.png" alt="Day.js" /></a></p> <p align="center">Fast <b>2kB</b> alternative to Moment.js with the same modern API</p> <p align="center"> <a href="https://bundlephobia.com/package/dayjs"><img src="https://img.shields.io/bundlephobia/minzip/dayjs?style=flat-square&color=%2345cc11" alt="Gzip Size"></a> <a href="https://www.npmjs.com/package/dayjs"><img src="https://img.shields.io/npm/v/dayjs.svg?style=flat-square&colorB=51C838" alt="NPM Version"></a> <a href="https://github.com/iamkun/dayjs/actions/workflows/check.yml"><img src="https://img.shields.io/github/actions/workflow/status/iamkun/dayjs/check.yml?style=flat-square" alt="Build Status"></a> <a href="https://codecov.io/gh/iamkun/dayjs"><img src="https://img.shields.io/codecov/c/github/iamkun/dayjs/master.svg?style=flat-square" alt="Codecov"></a> <a href="https://github.com/iamkun/dayjs/blob/master/LICENSE"><img src="https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square" alt="License"></a> <br> <a href="https://saucelabs.com/u/dayjs"> <img width="750" src="https://user-images.githubusercontent.com/17680888/40040137-8e3323a6-584b-11e8-9dba-bbe577ee8a7b.png" alt="Sauce Test Status"> </a> </p>Day.js is a minimalist JavaScript library that parses, validates, manipulates, and displays dates and times for modern browsers with a largely Moment.js-compatible API. If you use Moment.js, you already know how to use Day.js.
jsdayjs().startOf('month').add(1, 'day').set('year', 2018).format('YYYY-MM-DD HH:mm:ss');
- 🕒 Familiar Moment.js API & patterns
- 💪 Immutable
- 🔥 Chainable
- 🌐 I18n support
- 📦 2kb mini library
- 👫 All browsers supported
Getting Started
Documentation
You can find more details, API, and other docs on day.js.org website.
Installation
consolenpm install dayjs --save
API
It's easy to use Day.js APIs to parse, validate, manipulate, and display dates and times.
javascriptdayjs('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 them.
javascriptimport '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.
javascriptimport advancedFormat from 'dayjs/plugin/advancedFormat' // load on demand dayjs.extend(advancedFormat) // use plugin dayjs().format('Q Do k kk X x') // more available formats
Downloads

Sponsors
Support this project by becoming a sponsor. Your logo will show up here with a link to your website.
[Become a sponsor via Github] [Become a sponsor via OpenCollective]
<a href="https://github.com/ken-swyfft" target="_blank"> <img width="70" src="https://avatars.githubusercontent.com/u/65305317?v=4"> </a> <a href="https://opencollective.com/sight-sound" target="_blank"> <img width="70" src="https://images.opencollective.com/sight-sound/54f7220/logo/256.png?height=256"> </a> <a href="https://opencollective.com/filerev" target="_blank"> <img width="70" src="https://images.opencollective.com/filerev/93a8f05/logo/256.png?height=256" /> </a> <a href="https://opencollective.com/carboneio" target="_blank"> <img width="70" src="https://images.opencollective.com/carboneio/fe2066c/logo/256.png?height=256"> </a> <a href="https://www.netrouting.com" target="_blank" alt="Netrouting Dedicated Servers"> <img width="70" src="https://netrouting.com/wp-content/uploads/2026/04/Logo-netrouting.png"> </a> <a href="https://anonstories.com" target="_blank"> <img alt="Instagram Story Viewer" width="70" src="https://avatars.githubusercontent.com/u/240702364?v=4"> </a> <a href="https://www.sayfone.com/call-rates " target="_blank"> <img alt="Sayfone Cheap international calls" width="70" src="https://github.com/user-attachments/assets/68f91139-b190-421b-bcd7-43a8e3d84fe7"> </a> <a href="https://automatio.ai" target="_blank" alt="Automatio AI"> <img width="70" src="https://avatars.githubusercontent.com/u/1984909?v=4" /> </a> <a href="https://bestkru.com/" target="_blank"> <img width="70" src="https://avatars.githubusercontent.com/u/159320286" alt="BestKru"> </a> <a href="https://handsontable.com/docs/react-data-grid/?utm_source=Dayjs_GH&utm_medium=sponsorship&utm_campaign=library_sponsorship" target="_blank"> <img width="70" src="https://github.com/user-attachments/assets/426c3476-dc34-44d1-a904-ed58dbd20dd6"> </a> <a href="https://route4me.com/" target="_blank"> <img width="70" src="https://github.com/user-attachments/assets/3fbc86c5-98a9-49c2-beae-1969026fcd76" alt="Route Optimizer and Route Planner Software"> </a> <a href="https://github.com/sentdm" target="_blank"> <img width="70" src="https://avatars.githubusercontent.com/u/153308555?s=200&v=4"> </a> <a href="https://github.com/blacksandsmedia" target="_blank"> <img width="70" src="https://avatars.githubusercontent.com/u/116517387?v=4"> </a> <a href="https://github.com/mvpsnet" target="_blank"> <img width="70" src="https://avatars.githubusercontent.com/u/89784111?s=96&v=4"> </a> <a href="https://unaimytext.com" target="_blank"> <img width="70" src="https://github.com/user-attachments/assets/8510473a-c097-4bc9-8c61-b7515194f6f5"> </a>Contributors
This project exists thanks to all the people who contribute.
Please give us a 💖 star 💖 to support us. Thank you.
And thank you to all our backers! 🙏
<a href="https://opencollective.com/dayjs#backers" target="_blank"><img src="https://opencollective.com/dayjs/contributors.svg?width=890" /></a>
License
Day.js is licensed under a MIT License.
Contributors
Showing top 12 contributors by commit count.
