Moment.js

Moment.js is a JavaScript library that helps you manage dates, in the browser and in Node.js as well.

Note: Moment.js is now considered a legacy project in maintenance mode. For new projects, consider alternatives like date-fns, Luxon, or Day.js. However, Moment.js is still widely used in existing codebases.

Installation

You can include it directly in your page using a script tag:

<script src="https://unpkg.com/moment" />

Or using npm:

npm install moment

If you install using npm you need to import the package:

import moment from 'moment'

Or using CommonJS:

const moment = require('moment')

Get the current date and time

const date = moment()

Parse a date

A moment object can be initialized with a date by passing it a string:

const date = moment(string)

It accepts any string, parsed according to (in order):

• ISO 8601
• The RFC 2822 Date Time format
• The formats accepted by the Date object

ISO 8601 is definitely the most convenient. Here’s a format reference:

Format	Meaning	Example
YYYY	4-digits Year	2018
YY	2-digits Year	18
M	2-digits Month number, omits leading 0	7
MM	2-digits Month number	07
MMM	3-letters Month name	Jul
MMMM	Full Month name	July
dddd	Full day name	Sunday
gggg	4-digits Week year	2018
gg	2-digits Week year	18
w	Week of the year without leading zero	18
ww	Week of the year with leading zero	18
e	Day of the week, starts at 0	4
D	2-digits day number, omits leading 0	9
DD	2-digits day number	09
Do	Day number with ordinal	9th
T	Indicates the start of the time part
HH	2-digits hours (24 hour time) from 0 to 23	22
H	2-digits hours (24 hour time) without leading 0	22
kk	2-digits hours (24 hour time) from 1 to 24	23
k	2-digits hours (24 hour time) from 1 to 24 without leading 0	23
a/A	am or pm	pm
hh	2-digits hours (12 hour time)	11
mm	2-digits minutes	22
ss	2-digits seconds	40
s	2-digits seconds without leading zero	40
S	1-digits milliseconds	1
SS	2-digits milliseconds	12
SSS	3-digits milliseconds	123
Z	The timezone	+02:00
x	UNIX timestamp in milliseconds	1410432140575

Format a date

When you want to output the content of a plain JavaScript Date object, you have limited options to determine the formatting.

Moment offers a handy way to format the date according to your needs, using the format() method:

date.format(string)

The string format accepts the same formats described above.

Example:

moment().format("YYYY Do MM")

Moment provides some constants you can use instead of writing your own format:

Constant	Format	Example
moment.HTML5_FMT.DATETIME_LOCAL	YYYY-MM-DDTHH:mm	2017-12-14T16:34
moment.HTML5_FMT.DATETIME_LOCAL_SECONDS	YYYY-MM-DDTHH:mm:ss	2017-12-14T16:34:10
moment.HTML5_FMT.DATETIME_LOCAL_MS	YYYY-MM-DDTHH:mm:ss.SSS	2017-12-14T16:34:10.234
moment.HTML5_FMT.DATE	YYYY-MM-DD	2017-12-14
moment.HTML5_FMT.TIME	HH:mm	16:34
moment.HTML5_FMT.TIME_SECONDS	HH:mm:ss	16:34:10
moment.HTML5_FMT.TIME_MS	HH:mm:ss.SSS	16:34:10.234
moment.HTML5_FMT.WEEK	YYYY-[W]WW	2017-W50
moment.HTML5_FMT.MONTH	YYYY-MM	2017-12

Validating a date

Any date can be checked for validity using the isValid() method:

moment('2018-13-23').isValid() //false
moment('2018-11-23').isValid() //true

Time ago, time until date

Use fromNow(). Strings are localized:

moment('2016-11-23').fromNow() //2 years ago
moment('2018-05-23').fromNow() //a month ago
moment('2018-11-23').fromNow() //in 5 months

If you pass true to fromNow(), it just shows the difference, without reference to future/past:

moment('2016-11-23').fromNow(true) //2 years
moment('2018-05-23').fromNow(true) //a month
moment('2018-11-23').fromNow(true) //5 months

Manipulate a date

You can add or subtract any amount of time to a date:

moment('2016-11-23').add(1, 'years')
moment('2016-11-23').subtract(1, 'years')

You can use these values:

• years
• quarters
• months
• weeks
• days
• hours
• minutes
• seconds
• milliseconds

Lessons in this unit:

0:	Introduction
1:	jQuery
2:	Axios
3:	▶︎ Moment.js
4:	SWR
5:	XState
6:	PeerJS