Moment.js, A Simple Tool For Calculating Date And Time(feat.Nodejs)

Easy way to calculate date and time way better

Sometimes we need to calculate date and time.

Actually more than sometimes.

And this library, moment.js, is so powerful for your purpose.

Getting date, setting a date format whatsoever you want, subtracting date from date, counting days, and others.

Below listed some functions for your quick use.

Let’s dig it.

Install moment.js

Install library with below command.

npm install moment

Import the library with ‘require’ function.

var moment = require('moment');

//ES6 syntax
import moment from 'moment';

Let’s get started from parsing date.

const date = moment(""); //2022-01-23T11:15:00+09:00

We can display date using format() method with below tokens.

YY(YY) year ex) YYYY -> 2022, YY -> 22
MM(MM) monthex) MMMM -> January, MM -> 01
DD dateex) DD -> 25
dd(dd) dayex) dd -> Tu, dddd -> Tuesday
hhhour(12)ex) hh -> 01
HH hour(24)ex) HH -> 13
mm minuteex) mm -> 07
sssecondex) ss -> 03
a am, pmex) a -> pm
Do ordinalex) Do -> 25th
//January Tu 2022, 01:07:21 pm
moment.format('MMMM dd YYYY, hh:mm:ss a'); 

//January Tuesday 2022, pm 01:17
moment.format('MMMM dddd YYYY, a hh:mm') 

// 01/25/2022

isValid() method works well on it.

moment('2022-01-25','YYYY-MM-DD').isValid(); //true

moment('2022-02-30','YYYY-MM-DD').isValid(); //false

moment('My birth is 2022-1-25','YYYY-MM-DD').isValid(); //true

Also parsing every detail date is available by intuitive methods.

hour()get hour
minute()get minute
second()get second
millisecond()get millisecond
date()get date (1~31)
day()get day of week (0~6)
week()get week of year (1~53)
month()get month (0~11)
year()get year
moment(new Date).hour(); //13

moment().millisecond(); //331

moment().week(); //5

To get the difference in date, use diff() method.

const theDate = moment('2021-01-20', 'YYYY-MM-DD');
const myDate = moment('2022-01-25', 'YYYY-MM-DD');

myDate.diff(theDate, 'days');     // 5
myDate.diff(theDate, 'year');    // 1
myDate.diff(theDate, 'month');  // 12

We can use this method for counting expire date or calculate D-day.

And there is a bunch of methods this library thanks to the last long maintenance till today.

Please check official web for further infomation.