Concepts
DayJS is a lightweight JavaScript date API (2kB) which describe the same MomentJS API. (If you use Moment.js so could use easily Day.js )
Day.js is a minimalist and simple library that parses, validates, manipulates, and displays dates and times for modern browsers.
Why DayJS replace Momentjs
Tree-shaking: Moment doesn't work well with modern "tree shaking" algorithms, so it tends to increase the size of web application bundles.
Mutable: consider that Moment objects are mutable. Changing Moment to be immutable would be a breaking change for every one of the projects that use it.
Get Started
Installation
npm install dayjs
import dayjs from 'dayjs' // ES 2015
Parse
now = dayjs();
d = dayjs('2013-03-01', 'YYYY-MM-DD');
d = dayjs('2018-04-04T16:00:00.000Z') // ISO
d = dayjs(1318781876406) // Javascript timestamps -- Millis
d = dayjs.unix(1318781876) // Unix timestamps
d = new Date(2018, 8, 18) // Date object
d = dayjs({ years:2010, months:3, date:5, hours:15, minutes:10, seconds:3, milliseconds:123});
Format
d.format() // "2013-03-01T00:00:00+01:00"
d.format('dddd') // "Friday"
d.format('MMM Do YY') // "Mar 1st 13"
d.fromNow() // "7 years ago"
d.calendar() // "03/01/2013"
Get/Set
dayjs().second() // => new Date().getSeconds()
dayjs().second(30).valueOf() // => new Date().setSeconds(30)
dayjs().hour()
dayjs().hour(12)
Manipulate (Add-Substract)
d.add(1, 'day')
d.subtract(2, 'days')
d.startOf('day')
d.endOf('day')
d.startOf('hour')
Query
d.isBefore(dayjs('2011-01-01'))
d.isSame(dayjs('2011-01-01'))
d.isAfter(dayjs('2011-01-01'))
Bundlephobia
Top comments (6)
I've used dayjs in an Angular project to create a custom datepicker. It was not a very good experience honestly. I'll try date-fns or luxon next time
Agree. I using date-fns for my big project, it's awesome.
i use date-fns
dayjs is only good in the size but not the performance
Now this is a good library to use.
I used date-fns but dayjs looks awesome!
This is my go-to date library