Moment.js moment().diff() Function

The moment().diff() function is used to calculate the difference between two dates using Moment.js. By default, it returns the difference in milliseconds, but you can also specify a different unit (e.g., days, years) for the result.

Syntax:

moment().diff(Moment|String|Number|Date|Array, [String], [Boolean]);

Parameters:

• Moment|String|Number|Date|Array: The date to compare with the current moment.
• String (optional): The unit of time (e.g., 'days', 'months', 'years').
• Boolean (optional) :If true, returns a floating point number instead of an integer.

Return Value: This function returns the date in milliseconds.

The moment().diff() function calculates the difference between two dates in Moment.js.

Steps to create the application:

Step 1: You can install this package by using this command.

npm install express

Step 2: After installing the express module, you can check your express version in the command prompt using the command.

npm version express

Project Structure:

The updated dependencies in package.json file will look like:

"dependencies": {
    "express": "^5.1.0",
}

Example 1: Below is the code example of moment().diff() Function

// Requiring the module
const moment = require('moment');

let dateOne = moment([2019, 03, 17]);
let dateTwo = moment([2001, 10, 28]);

// Function call
let result = dateOne.diff(dateTwo, 'days') 

console.log("No of Days:", result)

Steps to Run the Program:

node index.js

Output:

No of Days: 6349

Example 2: Below is the code example of moment().diff() Function

// Requiring the module
const moment = require('moment');

function getYearDiff(dateOne, dateTwo) {
    return dateOne.diff(dateTwo, 'years', true);
}

// Function call
let result = getYearDiff(moment([2019, 11,
    30]), moment([2001, 2, 17]));

console.log("No of years difference:", result)

Steps to Run the Program:

node index.js

Output:

No of years difference: 18.78611111111111

Conclusion

Moment.js is still widely used, but it's now in maintenance mode and not recommended for new projects. Consider using modern alternatives like Luxon, date-fns, or Day.js for better performance and up-to-date features.