Libraries for Working with Dates in Node.js

Overview of Libraries for Working with Dates in JavaScript (Node.js)

Working with dates is one of the most common and simultaneously complex tasks in web development. In JavaScript, the native Date object has a number of drawbacks: mutability, limited formatting and parsing capabilities, and issues with time zones. Fortunately, the Node.js ecosystem offers several powerful libraries that significantly simplify date manipulation. In this article, we will look at four of the most popular ones: Moment.js, Day.js, date-fns, and Luxon.

1. Moment.js — A Classic of the Genre

For a long time, Moment.js was the de facto standard for working with dates. It provides a rich API for parsing, validation, manipulation, and display of dates. However, the library is considered deprecated (maintenance mode) and is not recommended for new projects due to its large size (about 300 KB) and performance issues.

Installation:

npm install moment

Usage Examples:

const moment = require('moment');

// Current dateconst now = moment();console.log(now.format('YYYY-MM-DD HH:mm:ss')); // 2025-03-15 14:30:00

// Parsing a stringconst date = moment('2025-12-31', 'YYYY-MM-DD');console.log(date.add(1, 'day').format('DD.MM.YYYY')); // 01.01.2026

// Difference between datesconst start = moment('2025-01-01');const end = moment('2025-03-15');console.log('Days passed:', end.diff(start, 'days')); // 73

2. Day.js — A Lightweight Alternative

Day.js is a minimalist library (only 2 KB) that is fully API-compatible with Moment.js. It is ideal for projects where bundle size is important. Day.js supports plugins for extending functionality (time zones, relative time, etc.).

Installation:

npm install dayjs

Usage Examples:

const dayjs = require('dayjs');const relativeTime = require('dayjs/plugin/relativeTime');const utc = require('dayjs/plugin/utc');

dayjs.extend(relativeTime);dayjs.extend(utc);

// Current dateconsole.log(dayjs().format('DD.MM.YYYY')); // 15.03.2025

// Relative timeconsole.log(dayjs('2025-03-10').fromNow()); // 5 days ago

// Working with UTCconsole.log(dayjs.utc().format()); // 2025-03-15T11:30:00Z

3. date-fns — A Functional Approach

date-fns is a modern library built on the principles of functional programming. Unlike Moment.js, it does not use mutable objects and supports tree-shaking, which allows you to import only the needed functions and reduce the bundle size.

Installation:

npm install date-fns

Usage Examples:

const { format, addDays, differenceInDays, parseISO } = require('date-fns');const { ru } = require('date-fns/locale');

// Formatting with localeconsole.log(format(new Date(), 'd MMMM yyyy', { locale: ru })); // 15 March 2025

// Manipulationconst future = addDays(new Date(), 10);console.log(format(future, 'yyyy-MM-dd')); // 2025-03-25

// Differenceconst d1 = parseISO('2025-01-01');const d2 = new Date();console.log('Days since New Year:', differenceInDays(d2, d1)); // 73

4. Luxon — The Modern Standard

Luxon is a library from the creators of Moment.js, but without their drawbacks. It uses native DateTime, Duration, and Interval objects, supports time zones and internationalization out of the box. Luxon is ideal for complex scenarios involving time zones.

Installation: