Welcome folks today in this blog post we will be talking about moment.js which is a date time manipulation library written in javascript. We will be talking in detail with practical examples about this library. All the source code of examples will be given below. Let’s get Started
Get Started
In order to get started you need to visit the official site of moment.js and download the library files and install it inside your root directory or you can include it from the cdn
Moment.js CDN
You can also get started by adding the moment.js library by including a CDN inside your html page and then you can use moment inside your javascript.
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<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script> |
Installing it By NPM
You can also use moment library inside your node.js application. You just need to execute the below command to install moment as a node dependency
npm i moment
Basic Example
Now to use the moment library and have a basic example of initializing a new date in moment
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var date = moment() console.log(date.fromNow()) |
Now you can see that in moment we have initialized a date and this has a special method fromNow() which returns the current time
Adding Days to Current Time
Now we will look at a example where we will add days to the current date and time in moment.js
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const today = moment(); const nextWeek = today.clone().add(7, 'days'); $("#result").html(nextWeek.format('dddd Do MMMM, YYYY')); |
In same way we can add minutes hours years and seconds to the current date and time in moment
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const today = moment(); const nextWeek = today.clone().add(7, 'years'); const nextWeek = today.clone().add(7, 'hours'); const nextWeek = today.clone().add(7, 'minutes'); const nextWeek = today.clone().add(7, 'seconds'); |
Subtracting Days From Current Date and Time
Now we will be looking at an example where we will be subtracting days,hours,minutes and seconds from the current date and time in moment.
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const today = moment(); const nextWeek = today.clone().subtract(7, 'years'); const nextWeek = today.clone().subtract(7, 'hours'); const nextWeek = today.clone().subtract(7, 'minutes'); const nextWeek = today.clone().subtract(7, 'seconds'); |
Difference Between Two Dates
Now in this examples we will be seeing how to calculate the difference between two dates in moment.js
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const dateB = moment('2014-11-11'); const dateC = moment('2014-10-11'); console.log('Difference is ', dateB.diff(dateC), 'milliseconds'); console.log('Difference is ', dateB.diff(dateC, 'days'), 'days'); console.log('Difference is ', dateB.diff(dateC, 'months'), 'months'); |
So now you can see in the examples we are using the diff() method to calculate the difference or subtract two dates in moment.js
Date Comparisons
In order to compare two dates in moment.js we have some useful methods which are namely isBefore(), isAfter(), and isSame()
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console.log(moment('2020-01-01').isAfter('2019-01-01')); // true console.log(moment('2020-01-01').isAfter('2020-01-08')); // false |
Checking Leap Year in Moment
In order to check whether a year is leap or not we have a special method isLeapYear() in moment.js.
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console.log(moment([2020]).isLeapYear()); // true console.log(moment([2019]).isLeapYear()); // false |
Date Validation
In order to validate dates inside your application in moment.js look at these examples
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console.log(moment("2020-01-01", "YYYY-MM-DD").isValid()); // true console.log(moment("not-a-date", "YYYY-MM-DD").isValid()); // false |
Node.js Example
At last we will be looking a node.js example where we will be using moment library.
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const moment = require('moment'); const today = moment(); const nextWeek = today.add(7, 'days'); console.log(today.fromNow()); |
