date-fns

What is date-fns?

The date-fns npm package provides a comprehensive, yet simple and consistent toolset for manipulating JavaScript dates in a browser & Node.js. It offers a variety of functions to parse, validate, manipulate, and format dates.

What are date-fns's main functionalities?

Parsing Dates

Parse strings in ISO format to JavaScript Date objects.

const parseISO = require('date-fns/parseISO');
const result = parseISO('2023-04-12');

Formatting Dates

Format Date objects into strings with a given format.

const format = require('date-fns/format');
const result = format(new Date(2023, 3, 12), 'yyyy-MM-dd');

Comparing Dates

Compare two dates to determine if one comes before the other.

const isBefore = require('date-fns/isBefore');
const result = isBefore(new Date(2023, 3, 12), new Date(2023, 3, 13));

Manipulating Dates

Perform date calculations such as adding or subtracting time spans.

const addDays = require('date-fns/addDays');
const result = addDays(new Date(2023, 3, 12), 10);

Validating Dates

Check if a date is valid.

const isValid = require('date-fns/isValid');
const result = isValid(new Date('2023-04-12'));

Other packages similar to date-fns

moment

Moment.js is a legacy project, now in maintenance mode, which provides similar functionalities for parsing, validating, manipulating, and formatting dates. It's more object-oriented and mutable compared to the functional and immutable design of date-fns.

dayjs

Day.js is a lightweight date library that offers a similar API to Moment.js but with a smaller footprint. It is immutable and chainable, like date-fns, but with a different plugin system for extending functionality.

luxon

Luxon is a powerful, modern, and chainable library for working with dates and times. It offers a rich set of features for parsing, formatting, manipulating, and querying dates. It's built on the Intl API and provides time zone support out of the box, which is more comprehensive than date-fns's approach to time zones.

README

date-fns

Date helpers in function-per-file style.

Installation

npm install --save date-fns

Usage

var isLastDayOfMonth = require('date-fns/src/is_last_day_of_month');
var date = new Date(2014, 1, 28);
console.log(isLastDayOfMonth(date));
//=> true

API

Code is fully documented, checkout source for reference.

Common helpers

• format - format date.
• isFuture - is passed date future?
• isEqual - are passed dates equal?
• isBefore - is first date before second one?
• isAfter - is first date after second one?
• compareAsc - compares the two dates and returns -1, 0 or 1.
• compareDesc - compares the two dates reverse chronologicaly and returns -1, 0 or 1.
• parse - parse ISO-8601-formatted date.

Range helpers

• isWithinRange - is passed date within range?

Minutes helpers

• addMinutes - add minutes to passed date.
• subMinutes - subtracts minutes from passed date.

Hours helpers

• startOfHour - returns start of an hour for passed date.
• endOfHour - returns end of an hour for passed date.
• addHours - add hours to passed date.
• subHours - subtracts hours from passed date.

Day helpers

• isWeekend - is passed date weekend?
• isToday - is passed date today?
• startOfDay - returns start of a day for passed date.
• endOfDay - returns end of a day for passed date.
• addDays - add specified number of days to passed date.
• subDays - subtract specified number of days from passed date.
• eachDay - returns array of dates within specified range.
• isSameDay - are parssed dates has the same day?

Week helpers

• getISOWeek - returns ISO week index.
• setISOWeek - sets ISO week index.
• startOfWeek - returns start of a week for passed date.
• endOfWeek - returns end of a week for passed date.
• isSameWeek - returns true if passed dates belongs to the same week.

Month helpers

• startOfMonth - returns start of a month for passed date.
• endOfMonth - returns end of a month for passed date.
• addMonths - add specified number of months to passed date.
• subMonths - subtract specified number of days from passed date.
• isSameMonth - returns true if passed dates has same month (and year).
• isFirstDayOfMonth - return true if passed date is first day of month.
• isLastDayOfMonth - return true if passed date is last day of month.
• setMonth - sets month index.

Year helpers

• getISOYear - returns ISO week-numbering year.
• setYear - sets full year.
• setISOYear - sets ISO week-numbering year.
• isSameYear - are passed dates has the same year?
• startOfYear - returns start of year for passed date.
• startOfISOYear - returns start of ISO week-numbering year for passed date.

I18n

TODO

Changelog

[0.14.11] - 2015-08-21

Fixed

• format now uses parse to avoid time zone bugs.

Changed

• setIsoWeek now sets time to the start of the day.