> 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');
```


## Getting Started

### Installation

```console
npm install dayjs --save
```


### 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
```

### I18n

Day.js has great support for internationalization.

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

```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
```


### 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
```

## License

Day.js is licensed under a [MIT License](./LICENSE).