JavaScript Add Months to Date


Manipulating dates in JavaScript often involves adding or subtracting specific time units to meet various application needs.

Adding months to a Date object is essential for scenarios like billing cycles 📆, project timelines 📅, or any instance requiring date-based calculations.

    Table of Contents

  1. Using setMonth() Method
  2. Using getTime() and setTime() Methods
  3. Using the Date Constructor
  4. Using Libraries like date-fns or moment.js
  5. Conclusion

1. Using setMonth() Method

The setMonth() method of the Date object allows us direct modification of the month 📅.

For this apply this method on any date object and pass the month number as an argument to it. To add months get the current month number and add the number of months you want to add to it.

Let's add 3 months to the current date.

Example

let date = new Date();
console.log(date);

// 📅 Adding 3 months
date.setMonth(date.getMonth() + 3);
console.log(date);

2. Using getTime() and setTime() Methods

This approach involves converting the date to milliseconds using getTime(), adding the required months in milliseconds, and then setting the updated time using setTime().

1 month = 30 days = 30 * 24 * 60 * 60 * 1000 milliseconds (approx.)

Example

let date = new Date();
console.log(date);

// 📅 Adding 3 months
date.setTime(date.getTime() + (30 * 24 * 60 * 60 * 1000 * 3));
console.log(date);

3. Using the Date Constructor

Date constructure can create a new date object by passing different arguments to it, like year, month, day, hour, minute, second, and millisecond.

So , just like the previous approach, we can pass milliseconds after adding the required months to the current date object.

Example

let date = new Date();
console.log(date);

// 📅 Adding 3 months
date = new Date(date.getTime() + (30 * 24 * 60 * 60 * 1000 * 3));
console.log(date);

4. Using Libraries like date-fns or moment.js

There are few third party libraries 📚 like date-fns or moment.js that provide a direct method to add months to a date object.

Using date-fns

To maniputale month in date-fns, we can use the addMonths() method.

var { addMonths } = require('date-fns');

let date = new Date();
console.log(date);

// 📅 Adding 3 months
date = addMonths(date, 3);
console.log(date);

Using moment.js

To manipulate month in moment.js, we can use the add() method by passing the number of months as first argument and 'months' as the second argument.

var moment = require('moment');

let date = new Date();
console.log(date);

// 📅 Adding 3 months
date = moment(date).add(3, 'months').toDate();
console.log(date);

Conclusion

Adding months to a JavaScript Date object encompasses various methods, each with its own advantages.

Whether employing native methods like setMonth() or getTime() with setTime(), or harnessing third-party libraries like date-fns or moment.js, mastering these methods empowers efficient management of month-based operations within your JavaScript applications.