You don't (may not) need Moment.js

Moment.js is a fantastic time & date library with lots of great features and utilities. However, if you are working on a performance sensitive web application, it might cause a huge performance overhead because of its complex APIs and large bundle size.

Problems with Moment.js:

• Highly based on OOP APIs, which makes it fail to work with tree-shaking, thus leading to a huge bundle size and performance issues.
• Moment.js is mutable due to OOP APIs and non-pure functions, which causes bugs: https://github.com/moment/moment/blob/develop/src/test/moment/add_subtract.js#L244-L286

Only using some simple functions from moment.js might be considered overkill. dayjs has a smaller core and has very similar APIs so it makes it very easy to migrate. date-fns enables tree-shaking and other benefits so that it works great with React, Sinon.js, and webpack, etc. See moment/moment#2373 for more ideas on why and how people switch from moment.js to other solutions.

Brief Comparison

Name	Size(gzip)	Tree-shaking	Popularity	Methods richness	Pattern	Timezone Support	Locale
Moment.js	329K(69.6K)	No	38k	High	OO	Good(moment-timezone)	123
date-fns	78.4k(13.4k) without tree-shaking	Yes	13k	High	Functional	Not yet	32
dayjs	6.5k(2.6k) without plugins	No	14k	Medium	OO	Not yet	23

Voice of Developers

Removed moment.js to replace with date-fns - build output reduced by 40%

—Jared Farago from webnode project.

Make use of native JavaScript object and array utilities before going big.Good library if you’re looking to replace Moment.js for one reason or another. Immutable too.

—Dan Abramov, Author of Co-author of Redux and Create React App. Building tools for humans.

I strongly recommend using date-fns over Moment.js, it's has a nicer API and you can include only parts you need!

—Matija Marohnić, a design-savvy frontend developer from Croatia.

Just yesterday changed momentjs to this lib in out project. Cut the size of our js bundle almost in half 😱

—Sergey Petushkov, a javaScript developer from Moscow, Russia • Currently in Berlin, Germany.

ESLint Plugin

If you're using ESLint, you can install a plugin that will help you identify places in your codebase where you don't (may not) need Moment.js.

Install the plugin...

npm install --save-dev eslint-plugin-you-dont-need-momentjs

...then update your config

"extends" : ["plugin:you-dont-need-momentjs/recommended"],

Quick Links

Parse

1. String + Date Format
2. String + Time Format
3. String + Format + locale

Get + Set

1. Millisecond/Second/Minute/Hour
2. Date of Month
3. Day of Week
4. Day of Year
5. Week of Year
6. Days in Month
7. Weeks in Year
8. Maximum of the given dates
9. Minimum of the given dates

Manipulate

1. Add
2. Subtract
3. Start of Time
4. End of Time

Display

1. Format
2. Time from now
3. Time from X
4. Difference

Query

1. Is Before
2. Is Same
3. Is After
4. Is Between
5. Is Leap Year
6. Is a Date

⚠️ Note that the version of date-fns used in this example is v2, See v1 docs

Parse

String + Date Format

Return the date parsed from date string using the given format string.

// Moment.js
moment('12-25-1995', 'MM-DD-YYYY');
// => "1995-12-24T13:00:00.000Z"

// date-fns
import parse from 'date-fns/parse';
parse('12-25-1995', 'MM-dd-yyyy', new Date());
// => "1995-12-24T13:00:00.000Z"

// dayjs
dayjs('12-25-1995');
// => "1995-12-24T13:00:00.000Z"

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String + Time Format

Return the date parsed from time string using the given format string.

// Moment.js
moment('2010-10-20 4:30', 'YYYY-MM-DD HH:mm');
// => "2010-10-19T17:30:00.000Z"

// date-fns
import parse from 'date-fns/parse';
parse('2010-10-20 4:30', 'yyyy-MM-dd H:mm', new Date());
// => "2010-10-19T17:30:00.000Z"

// dayjs ❌ does not support custom format parse

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String + Format + locale

Return the date parsed from string using the given format string and locale.

// Moment.js
moment('2012 mars', 'YYYY MMM', 'fr');
// => "2012-02-29T13:00:00.000Z"

// date-fns
import parse from 'date-fns/parse';
import fr from 'date-fns/locale/fr';
parse('2012 mars', 'yyyy MMMM', new Date(), { locale: fr });
// => "2012-02-29T13:00:00.000Z"

// dayjs ❌ does not support custom format parse

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Get + Set

Millisecond / Second / Minute / Hour

Get the Millisecond/Second/Minute/Hour of the given date.

// Moment.js
moment().seconds();
// => 49
moment().hours();
// => 19

// Native
new Date().getSeconds();
// => 49
new Date().getHours();
// => 19

// date-fns
import getSeconds from 'date-fns/getSeconds';
import getHours from 'date-fns/getHours';
getSeconds(new Date());
// => 49
getHours(new Date());
// => 19

// dayjs
dayjs().second();
// => 49
dayjs().hour();
// => 19

Set the Millisecond/Second/Minute/Hour of the given date.

// Moment.js
moment().seconds(30);
// => "2018-09-09T09:12:30.695Z"
moment().hours(13);
// => "2018-09-09T03:12:49.695Z"

// Native
new Date(new Date().setSeconds(30));
// => "2018-09-09T09:12:30.695Z"
new Date(new Date().setHours(13));
// => "2018-09-09T03:12:49.695Z"

// date-fns
import setSeconds from 'date-fns/setSeconds';
import setHours from 'date-fns/setHours';
setSeconds(new Date(), 30);
// => "2018-09-09T09:12:30.695Z"
setHours(new Date(), 13);
// => "2018-09-09T03:12:49.695Z"

// dayjs
dayjs().set('second', 30);
// => "2018-09-09T09:12:30.695Z"
dayjs().set('hour', 13);
// => "2018-09-09T03:12:49.695Z"

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Date of Month

Gets or sets the day of the month.

// Moment.js
moment().date();
// => 9
moment().date(4);
// => "2018-09-04T09:12:49.695Z"

// Native
new Date().getDate();
// => 9
new Date().setDate(4);
// => "2018-09-04T09:12:49.695Z"

// date-fns
import getDate from 'date-fns/getDate';
import setDate from 'date-fns/setDate';
getDate(new Date());
// => 9
setDate(new Date(), 4);
// => "2018-09-04T09:12:49.695Z"

// dayjs
dayjs().date();
// => 9
dayjs().set('date', 4);
// => "2018-09-04T09:12:49.695Z"

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Day of Week

Gets or sets the day of the week.

// Moment.js
moment().day();
// => 0 (Sunday)
moment().day(-14);
// => "2018-08-26T09:12:49.695Z"

// Native
new Date().getDay();
// => 0 (Sunday)
new Date().setDate(new Date().getDate() - 14);
// => "2018-08-26T09:12:49.695Z"

// date-fns
import getDay from 'date-fns/getDay';
import setDay from 'date-fns/setDay';
getDay(new Date());
// => 0 (Sunday)
setDay(new Date(), -14);
// => "2018-08-26T09:12:49.695Z"

// dayjs
dayjs().day();
// => 0 (Sunday)
dayjs().set('day', -14);
// => "2018-08-26T09:12:49.695Z"

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Day of Year

Gets or sets the day of the year.

// Moment.js
moment().dayOfYear();
// => 252
moment().dayOfYear(256);
// => "2018-09-13T09:12:49.695Z"

// date-fns
import getDayOfYear from 'date-fns/getDayOfYear';
import setDayOfYear from 'date-fns/setDayOfYear';
getDayOfYear(new Date());
// => 252
setDayOfYear(new Date(), 256);
// => "2018-09-13T09:12:49.695Z"

// dayjs ❌ does not support day of year

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Week of Year

Gets or sets the week of the year.

// Moment.js
moment().week();
// => 37
moment().week(24);
// => "2018-06-10T09:12:49.695Z"

// date-fns
import getWeek from 'date-fns/getWeek';
import setWeek from 'date-fns/setWeek';
getWeek(new Date());
// => 37
setWeek(new Date(), 24);
// => "2018-06-10T09:12:49.695Z"

// dayjs ⚠️ requires weekOfYear plugin
import weekOfYear from 'dayjs/plugin/weekOfYear';
dayjs.extend(weekOfYear);
dayjs().week();
// => 37
// dayjs ❌ does not support set week of year

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Days in Month

Get the number of days in the current month.

// Moment.js
moment('2012-02', 'YYYY-MM').daysInMonth();
// => 29

// date-fns
import getDaysInMonth from 'date-fns/getDaysInMonth';
getDaysInMonth(new Date(2012, 1));
// => 29

// dayjs
dayjs('2012-02').daysInMonth();
// => 29

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Weeks in Year

Gets the number of weeks in the current year, according to ISO weeks.

// Moment.js
moment().isoWeeksInYear();
// => 52

// date-fns
import getISOWeeksInYear from 'date-fns/getISOWeeksInYear';
getISOWeeksInYear(new Date());
// => 52

// dayjs ❌ does not support weeks in the year

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Maximum of the given dates

Returns the maximum (most distant future) of the given date.

const array = [
  new Date(2017, 4, 13),
  new Date(2018, 2, 12),
  new Date(2016, 0, 10),
  new Date(2016, 0, 9),
];
// Moment.js
moment.max(array.map(a => moment(a)));
// => "2018-03-11T13:00:00.000Z"

// Native
new Date(Math.max.apply(null, array)).toISOString();
// => "2018-03-11T13:00:00.000Z"

// date-fns
import max from 'date-fns/max';
max(array);
// => "2018-03-11T13:00:00.000Z"

// dayjs ❌ does not support the maximum of the given dates

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Minimum of the given dates

Returns the minimum (most distant future) of the given date.

const array = [
  new Date(2017, 4, 13),
  new Date(2018, 2, 12),
  new Date(2016, 0, 10),
  new Date(2016, 0, 9),
];
// Moment.js
moment.min(array.map(a => moment(a)));
// => "2016-01-08T13:00:00.000Z"

// Native
new Date(Math.min.apply(null, array)).toISOString();
// => "2016-01-08T13:00:00.000Z"

// date-fns
import min from 'date-fns/min';
min(array);
// => "2016-01-08T13:00:00.000Z"

// dayjs ❌ does not support the minimum of the given dates

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Manipulate

Add

Add the specified number of days to the given date.

// Moment.js
moment().add(7, 'days');
// => "2018-09-16T09:12:49.695Z"

// date-fns
import addDays from 'date-fns/addDays';
addDays(new Date(), 7);
// => "2018-09-16T09:12:49.695Z"

// dayjs
dayjs().add(7, 'day');
// => "2018-09-16T09:12:49.695Z"

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Subtract

Subtract the specified number of days from the given date.

// Moment.js
moment().subtract(7, 'days');
// => "2018-09-02T09:12:49.695Z"

// date-fns
import subDays from 'date-fns/subDays';
subDays(new Date(), 7);
// => "2018-09-02T09:12:49.695Z"

// dayjs
dayjs().subtract(7, 'day');
// => "2018-09-02T09:12:49.695Z"

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Start of Time

Return the start of a unit of time for the given date.

// Moment.js
moment().startOf('month');
// => "2018-08-31T14:00:00.000Z"

// date-fns
import startOfMonth from 'date-fns/startOfMonth';
startOfMonth(new Date());
// => "2018-08-31T14:00:00.000Z"

// dayjs
dayjs().startOf('month');
// => "2018-08-31T14:00:00.000Z"

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End of Time

Return the end of a unit of time for the given date.

// Moment.js
moment().endOf('day');
// => "2018-09-09T13:59:59.999Z"

// date-fns
import endOfDay from 'date-fns/endOfDay';
endOfDay(new Date());
// => "2018-09-09T13:59:59.999Z"

// dayjs
dayjs().endOf('day');
// => "2018-09-09T13:59:59.999Z"

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Display

Format

Return the formatted date string in the given format.

// Moment.js
moment().format('dddd, MMMM Do YYYY, h:mm:ss A');
// => "Sunday, September 9th 2018, 7:12:49 PM"
moment().format('ddd, hA');
// => "Sun, 7PM"

// date-fns
import format from 'date-fns/format';
format(new Date(), 'eeee, MMMM do YYYY, h:mm:ss aa');
// => "Sunday, September 9th 2018, 7:12:49 PM"
format(new Date(), 'eee, ha');
// => "Sun, 7PM"

// dayjs
dayjs().format('dddd, MMMM D YYYY, h:mm:ss A');
// => "Sunday, September 9 2018, 7:12:49 PM" ⚠️  not support 9th
dayjs().format('ddd, hA');
// => "Sun, 7PM"

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Time from now

Return time from now.

// Moment.js
moment(1536484369695).fromNow();
// => "4 days ago"

// date-fns
import formatDistance from 'date-fns/formatDistance';
formatDistance(new Date(1536484369695), new Date(), { addSuffix: true });
// => "4 days ago"

// dayjs ⚠️ requires relativeTime plugin
import relativeTime from 'dayjs/plugin/relativeTime';
dayjs.extend(relativeTime);

dayjs(1536484369695).fromNow();
// => "5 days ago" ⚠️  the rounding method of this plugin is different from moment.js and date-fns, use with care.

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Time from x

Return time from x.

// Moment.js
moment([2007, 0, 27]).to(moment([2007, 0, 29]));
// => "in 2 days"

// date-fns
import formatDistance from 'date-fns/formatDistance';
formatDistance(new Date(2007, 0, 27), new Date(2007, 0, 29));
// => "2 days"

// dayjs ⚠️ requires relativeTime plugin
import relativeTime from 'dayjs/plugin/relativeTime';
dayjs.extend(relativeTime);
dayjs('2007-01-27').to(dayjs('2007-01-29'));
// => "in 2 days"

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Difference

Get the unit of time between the given dates.

// Moment.js
moment([2007, 0, 27]).diff(moment([2007, 0, 29]));
// => -172800000
moment([2007, 0, 27]).diff(moment([2007, 0, 29]), 'days');
// => -2

// date-fns
import differenceInMilliseconds from 'date-fns/differenceInMilliseconds';
differenceInMilliseconds(new Date(2007, 0, 27), new Date(2007, 0, 29));
// => -172800000
import differenceInDays from 'date-fns/differenceInDays';
differenceInDays(new Date(2007, 0, 27), new Date(2007, 0, 29));
// => -2

// dayjs
dayjs('2007-01-27').diff(dayjs('2007-01-29'), 'milliseconds');
// => -172800000
dayjs('2007-01-27').diff(dayjs('2007-01-29'), 'days');
// => -2

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Query

Is Before

Check if a date is before another date.

// Moment.js
moment('2010-10-20').isBefore('2010-10-21');
// => true

// date-fns
import isBefore from 'date-fns/isBefore';
isBefore(new Date(2010, 9, 20), new Date(2010, 9, 21));
// => true

// dayjs
dayjs('2010-10-20').isBefore('2010-10-21');
// => true

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Is Same

Check if a date is same another date.

// Moment.js
moment('2010-10-20').isSame('2010-10-21');
// => false
moment('2010-10-20').isSame('2010-10-20');
// => true
moment('2010-10-20').isSame('2010-10-21', 'month');
// => true

// date-fns
import isSameDay from 'date-fns/isSameDay';
import isSameMonth from 'date-fns/isSameMonth';
isSameDay(new Date(2010, 9, 20), new Date(2010, 9, 21));
// => false
isSameDay(new Date(2010, 9, 20), new Date(2010, 9, 20));
// => true
isSameMonth(new Date(2010, 9, 20), new Date(2010, 9, 21));
// => true

// dayjs
dayjs('2010-10-20').isSame('2010-10-21');
// => false
dayjs('2010-10-20').isSame('2010-10-20');
// => true
// dayjs ❌ does not support is same month

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Is After

Check if a date is after another date.

// Moment.js
moment('2010-10-20').isAfter('2010-10-19');
// => true

// date-fns
import isAfter from 'date-fns/isAfter';
isAfter(new Date(2010, 9, 20), new Date(2010, 9, 19));
// => true

// dayjs
dayjs('2010-10-20').isAfter('2010-10-19');
// => true

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Is Between

Check if a date is between two other dates.

// Moment.js
moment('2010-10-20').isBetween('2010-10-19', '2010-10-25');
// => true

// date-fns
import isWithinInterval from 'date-fns/isWithinInterval';
isWithinInterval(new Date(2010, 9, 20), {
  start: new Date(2010, 9, 19),
  end: new Date(2010, 9, 25),
});
// => true

// dayjs ⚠️ requires isBetween plugin
import isBetween from 'dayjs/plugin/isBetween';
dayjs.extend(isBetween);
dayjs('2010-10-20').isBetween('2010-10-19', '2010-10-25');
// => true

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Is Leap Year

Check if a year is a leap year.

// Moment.js
moment([2000]).isLeapYear();
// => true

// date-fns
import isLeapYear from 'date-fns/isLeapYear';
isLeapYear(new Date(2000, 0, 1));
// => true

// dayjs ⚠️ requires isLeapYear plugin
import isLeapYear from 'dayjs/plugin/isLeapYear';
dayjs.extend(isLeapYear);
dayjs('2000').isLeapYear();
// => true

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Is a Date

Check if a variable is a native js Date object.

// Moment.js
moment.isDate(new Date());
// => true

// date-fns
import isDate from 'date-fns/isDate';
isDate(new Date());
// => true

// dayjs ❌ does not support is date

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License

MIT