Moment.js Playground & Day.js Migration

Try Moment.js formats live and see the Day.js equivalent side by side

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Moment.js is in maintenance mode, and its own team recommends a modern library for new projects. Day.js keeps nearly the same API in about 2 KB, so every section here also shows the Day.js equivalent.

Moment project status Open the Day.js playground

Loading Moment.js…

Format playground

Format string

Output

Moment.js · Code

import moment from 'moment'

moment('').format('YYYY-MM-DD HH:mm:ss')
// →

Format tokens

Click a token to insert it into the format string. Examples use the reference date and locale.

Token	Example	Meaning
Year and quarter
		Four-digit year
		Two-digit year
		Quarter (1–4)
		Quarter, ordinal
Month
		Month (1–12)
		Month, ordinal
		Month, two digits
		Month, short name
		Month, full name
Day of month and year
		Day of month
		Day of month, ordinal
		Day of month, two digits
		Day of year
		Day of year, three digits
Day of week
		Day of week (0 = Sunday)
		Weekday, shortest name
		Weekday, short name
		Weekday, full name
		Day of week, by locale
		ISO day of week (1 = Monday)
Week
		Week of year, by locale
		Week of year, ordinal
		Week of year, two digits
		ISO week of year
		ISO week, two digits
		Week-numbering year, by locale
		ISO week-numbering year
Hour
		Hour, 0–23
		Hour, 00–23
		Hour, 1–12
		Hour, 01–12
		Hour, 1–24
		Hour, 01–24
Minute and second
		Minute
		Minute, two digits
		Second
		Second, two digits
		Tenths of a second
		Hundredths of a second
		Milliseconds
AM / PM
		AM / PM
		am / pm
Time zone
		UTC offset, ±HH:mm
		UTC offset, ±HHmm
	needs moment-timezone	Time zone abbreviation
	needs moment-timezone	Time zone name
Unix time
		Unix seconds
		Unix milliseconds
Localized formats
		Localized time
		Localized time with seconds
		Localized numeric date
		Localized date with month name
		Localized date and time
		Localized date and time with weekday
		Short numeric date
		Short date with month name
		Short date and time
		Short date and time with weekday
Escaping
		Text in square brackets is printed as is

Parse playground

Date string

Expected format

Leave empty to parse ISO 8601.

Strict parsingThe input must match the format exactly.

Moment.js · Code

import moment from 'moment'

const d = moment('13/10/2026 14:30', 'DD/MM/YYYY HH:mm')
d.isValid()     // → false
d.toISOString() // → Invalid Date

Relative time

Each row shifts the reference date, then describes it relative to the reference with from() and calendar().

Shift	from(ref)	calendar(ref)
.add(-45, 'second')
.add(-10, 'minute')
.add(-3, 'hour')
.add(-1, 'day')
.add(-5, 'day')
.add(-3, 'month')
.add(-2, 'year')
.add(30, 'minute')
.add(2, 'day')
.add(1, 'month')

Moment.js · Code

import moment from 'moment'

const ref = moment('')
const t = ref.add(-3, 'hours')
t.from(ref)     // 
t.calendar(ref) //

Durations

Amount

Unit

Or an ISO 8601 duration

Moment.js · Code

import moment from 'moment'

const d = moment.duration(90, 'minutes')
d.humanize()    // → 
d.toISOString() // →

Recipes

Everyday tasks with live results. “Try” loads one into the code runner below.

Moment objects are mutable: add() changes the original. Day.js returns a new object from every operation, so reassign the result.

Task	Moment.js
Format the current time	`moment().format('YYYY-MM-DD HH:mm:ss')` →
Add days	`moment('2023-01-01').add(1, 'days').format('YYYY-MM-DD')` →
Time from now	`moment().subtract(7, 'days').fromNow()` →
First day of this month	`moment().startOf('month').format('YYYY-MM-DD')` →
Last day of this year	`moment().endOf('year').format('YYYY-MM-DD')` →
Start of this week (locale aware)	`moment().startOf('week').format('YYYY-MM-DD ddd')` →
Days between two dates	`moment().diff(moment('2022-01-01'), 'days')` →
Days in this month	`moment().daysInMonth()` →
Quarter of the year	`moment().quarter()` →
Calendar time	`moment().add(1, 'days').calendar()` →
Is a date between two others	`moment('2024-12-31').isBetween('2024-01-01', '2025-01-01')` →
Is it today	`moment().isSame(moment(), 'day')` →
Is it a leap year	`moment('2024-01-01').isLeapYear()` →
Validate a date strictly	`moment('2023-02-30', 'YYYY-MM-DD', true).isValid()` →
Parse a custom format	`moment('13/10/2026 14:30', 'DD/MM/YYYY HH:mm').format()` →
Unix timestamp in seconds	`moment().unix()` →
Current time in UTC	`moment.utc().format()` →
Time in another time zone	needs moment-timezone
Humanize a duration	`moment.duration(90, 'minutes').humanize()` →
Add a month at the end of a month	`moment('2026-01-31').add(1, 'months').format('YYYY-MM-DD')` →
Call add() without reassigning	`(() => { const d = moment('2026-01-01'); d.add(1, 'days'); return d.format('YYYY-MM-DD') })()` →

Code runner

Type an expression that uses moment. It runs right here in your browser, with every plugin from the recipes enabled and the locale above.

Moment.js

Result

Token

Example

Meaning

Year and quarter

Four-digit year

Two-digit year

Quarter (1–4)

Quarter, ordinal

Month

Month (1–12)

Month, ordinal

Month, two digits

Month, short name

Month, full name

Day of month and year

Day of month

Day of month, ordinal

Day of month, two digits

Day of year

Day of year, three digits

Day of week

Day of week (0 = Sunday)

Weekday, shortest name

Weekday, short name

Weekday, full name

Day of week, by locale

ISO day of week (1 = Monday)

Week

Week of year, by locale

Week of year, ordinal

Week of year, two digits

ISO week of year

ISO week, two digits

Week-numbering year, by locale

ISO week-numbering year

Hour

Hour, 0–23

Hour, 00–23

Hour, 1–12

Hour, 01–12

Hour, 1–24

Hour, 01–24

Minute and second

Minute

Minute, two digits

Second

Second, two digits

Tenths of a second

Hundredths of a second

Milliseconds

AM / PM

am / pm

Time zone

UTC offset, ±HH:mm

UTC offset, ±HHmm

needs moment-timezone

Time zone abbreviation

needs moment-timezone

Time zone name

Unix time

Unix seconds

Unix milliseconds

Localized formats

Localized time

Localized time with seconds

Localized numeric date

Localized date with month name

Localized date and time

Localized date and time with weekday

Short numeric date

Short date with month name

Short date and time

Short date and time with weekday

Escaping

Text in square brackets is printed as is

Shift

from(ref)

calendar(ref)

.add(-45, 'second')

.add(-10, 'minute')

.add(-3, 'hour')

.add(-1, 'day')

.add(-5, 'day')

.add(-3, 'month')

.add(-2, 'year')

.add(30, 'minute')

.add(2, 'day')

.add(1, 'month')

Task

Moment.js

Format the current time

moment().format('YYYY-MM-DD HH:mm:ss')

→

Add days

moment('2023-01-01').add(1, 'days').format('YYYY-MM-DD')

→

Time from now

moment().subtract(7, 'days').fromNow()

→

First day of this month

moment().startOf('month').format('YYYY-MM-DD')

→

Last day of this year

moment().endOf('year').format('YYYY-MM-DD')

→

Start of this week (locale aware)

moment().startOf('week').format('YYYY-MM-DD ddd')

→

Days between two dates

moment().diff(moment('2022-01-01'), 'days')

→

Days in this month

moment().daysInMonth()

→

Quarter of the year

moment().quarter()

→

Calendar time

moment().add(1, 'days').calendar()

→

Is a date between two others

moment('2024-12-31').isBetween('2024-01-01', '2025-01-01')

→

Is it today

moment().isSame(moment(), 'day')

→

Is it a leap year

moment('2024-01-01').isLeapYear()

→

Validate a date strictly

moment('2023-02-30', 'YYYY-MM-DD', true).isValid()

→

Parse a custom format

moment('13/10/2026 14:30', 'DD/MM/YYYY HH:mm').format()

→

Unix timestamp in seconds

moment().unix()

→

Current time in UTC

moment.utc().format()

→

Time in another time zone

needs moment-timezone

Humanize a duration

moment.duration(90, 'minutes').humanize()

→

Add a month at the end of a month

moment('2026-01-31').add(1, 'months').format('YYYY-MM-DD')

→

Call add() without reassigning

(() => { const d = moment('2026-01-01'); d.add(1, 'days'); return d.format('YYYY-MM-DD') })()

→

How to use Moment.js Playground & Day.js Migration

Test Moment.js formatting, parsing, relative time and durations, with the Day.js result shown next to every Moment result. Differences are flagged, so you can see what would change before migrating a codebase. Both libraries run in your browser.

Set the Reference date and time and a Locale, and turn on Treat as UTC if your code uses moment.utc().

Type a pattern into Format string; the Output shows Moment’s result and what Day.js gives, marked Same output or Different output.

Check the Format tokens table for tokens that Day.js lacks or needs a plugin for, and click a token to insert it.

Compare the two libraries in Parse playground, Relative time and Durations, where Day.js values that differ are highlighted.

Use Recipes for side-by-side code of everyday tasks, and click Try to run the Moment version in the Code runner.

Frequently asked questions

Is Moment.js still maintained?

Moment.js is in maintenance mode, and its own team recommends a modern library for new projects. The note at the top links to the Moment project status page and to the Day.js playground.

What usually breaks when switching to Day.js?

Mutability: Moment’s add() changes the original object, while Day.js returns a new one, so results must be reassigned. Many features also need Day.js plugins, which each recipe lists.

Which format tokens have no Day.js equivalent?

Qo, Mo, DDD, DDDD, e, E, S and SS. The Format tokens table marks them as not in Day.js and names the plugin needed for the others.

Why don’t the z and zzz tokens work in Moment?

Time zone names need the separate moment-timezone add-on, which this page doesn’t load, so the table shows needs moment-timezone. Day.js provides them through its timezone plugin.

Which versions are compared?

The exact Moment.js and Day.js versions are shown under the settings panel.

Is my code sent to a server?

No. Both libraries and their locale files load into this page, and everything you type is evaluated in your browser.

How to use Moment.js Playground & Day.js Migration

Set the Reference date and time and a Locale, and turn on Treat as UTC if your code uses moment.utc().

Type a pattern into Format string; the Output shows Moment’s result and what Day.js gives, marked Same output or Different output.

Check the Format tokens table for tokens that Day.js lacks or needs a plugin for, and click a token to insert it.

Compare the two libraries in Parse playground, Relative time and Durations, where Day.js values that differ are highlighted.

Use Recipes for side-by-side code of everyday tasks, and click Try to run the Moment version in the Code runner.

Frequently asked questions

Is Moment.js still maintained?

Moment.js is in maintenance mode, and its own team recommends a modern library for new projects. The note at the top links to the Moment project status page and to the Day.js playground.

What usually breaks when switching to Day.js?

Mutability: Moment’s add() changes the original object, while Day.js returns a new one, so results must be reassigned. Many features also need Day.js plugins, which each recipe lists.

Which format tokens have no Day.js equivalent?

Qo, Mo, DDD, DDDD, e, E, S and SS. The Format tokens table marks them as not in Day.js and names the plugin needed for the others.

Why don’t the z and zzz tokens work in Moment?

Time zone names need the separate moment-timezone add-on, which this page doesn’t load, so the table shows needs moment-timezone. Day.js provides them through its timezone plugin.

Which versions are compared?

The exact Moment.js and Day.js versions are shown under the settings panel.

Is my code sent to a server?

No. Both libraries and their locale files load into this page, and everything you type is evaluated in your browser.