GitPedia

Dayjs

⏰ Day.js 2kB immutable date-time library alternative to Moment.js with the same modern API

From iamkun·Updated June 23, 2026·View on GitHub·

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.

Latest release: v1.11.21
May 26, 2026View Changelog →

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.

js
dayjs().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

console
npm install dayjs --save

📚Installation Guide

API

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

javascript
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

📚API Reference

I18n

Day.js has great support for internationalization.

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

javascript
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

📚Internationalization

Plugin

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

javascript
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

📚Plugin List

Downloads

Day.js Chart

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]

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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.

View all contributors on GitHub →

This article is auto-generated from iamkun/dayjs via the GitHub API.Last fetched: 6/23/2026