A short introduction to javascript’s Date object

Javascript’s Date object and its method

Javascript’s Date Object

Here is a short introduction to javascript’s Date Object. we will look at the Date object and some practical methods of it. Date object allows us to create, manipulate, and format dates.

Javascript stores date as a number of milliseconds since midnight at the beginning of January 1 1970 UTC ( Universal Time Coordinated ).

Constructor

Date() constructor is used to create a new Date object. when we call Date() as a function it returns a string that contains the current date and time.

const CurrentDateTime = Date(); // calling as function

console.log(CurrentDateTime); 

// output : Wed Mar 22 2023 15:13:04 GMT+0530 (India Standard Time)

When we call Date as a constructor it returns a new Date object.

const CurrentDateTime = new Date(); // calling as constructor

console.log(CurrentDateTime); 
// 2023-03-22T09:49:05.158Z

There are 9 different ways to create a Date object. here is an example of it.

• year integer value describes the year.
• month integer value describes the month. where 0 is January and 11 is December.
• day integer value describes the day of the month.
• hours integer value between 0 to 23 describes the hours of the day.
• minutes integer value describes the minutes of the date time.
• seconds integer value describes the second of a time.
• milliseconds integer value describes milliseconds of a time.

// new Date()
// new Date(date string)
// new Date(year,month)
// new Date(year,month,day)
// new Date(year,month,day,hours)
// new Date(year,month,day,hours,minutes)
// new Date(year,month,day,hours,minutes,seconds)
// new Date(year,month,day,hours,minutes,seconds,ms)

const a = new Date();
// Wed Mar 22 2023 15:31:48 GMT+0530 (India Standard Time)

const b = new Date("March 22, 2023 15:13:00");
// Wed Mar 22 2023 15:13:00 GMT+0530 (India Standard Time)

const c = new Date(2023, 2);
// Wed Mar 01 2023 00:00:00 GMT+0530 (India Standard Time)

const d = new Date(2023, 2, 2);
// Thu Mar 02 2023 00:00:00 GMT+0530 (India Standard Time)

const e = new Date(2023, 2, 22,1);
// 2023-03-21T19:30:00.000Z

const f = new Date(2023, 2, 22, 1,20);
// 2023-03-21T19:50:00.000Z

const g = new Date(2023, 2, 22, 1, 20, 10);
// 2023-03-21T19:50:10.000Z

const h = new Date(2023, 2, 22, 1, 20, 10,12);
// 2023-03-21T19:50:10.012Z 

Useful Methods

Get Methods

getDate() method returns the day of the month (0–31).

const a = new Date("March 22, 2023 15:13:00");
const day = a.getDate();

console.log(day); // 22

getDay() method returns the day of the week (0–6) where 0 is Sunday and 6 is Saturday.

const a = new Date("March 22, 2023 15:13:00");
const dayOfWeek = a.getDay();

console.log(dayOfWeek); // 3

getFullYear() method returns the year. it is a four-digit number.

const a = new Date("March 22, 2023 15:13:00");
const fullYear = a.getFullYear();

console.log(fullYear); // 2023

getHours() method returns hours for the specified date (0–23).

const a = new Date("March 22, 2023 15:13:00");
const hours = a.getHours();

console.log(hours); // 15

getMilliseconds() method returns milliseconds for the specified date (0–999).

const a = new Date("March 22, 2023 15:13:20:10");
const milliSeconds = a.getMilliseconds();

console.log(milliSeconds); // 10

getMinutes() method returns minutes for the specified date (0–59).

const a = new Date("March 22, 2023 15:13:20:10");
const minutes = a.getMinutes();

console.log(minutes); // 13

getMonth() method returns the month for the specified date (0–11).

const a = new Date("March 22, 2023 15:13:20:10");
const month = a.getMonth();

console.log(month); // 2

getSeconds() method returns the seconds for the specified date (0–59).

const a = new Date("March 22, 2023 15:13:20:10");
const seconds = a.getSeconds();

console.log(seconds); // 20

Set Methods

setDate() method sets the day of the month of the date.

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getDate()); // 22
a.setDate(2);
console.log(a.getDate()); // 2

setFullYear() method sets the year of the date.

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getFullYear()); // 2023
a.setFullYear(2019);
console.log(a.getFullYear()); // 2019

setHours() method sets the hour of the date.

// we have different setHours method like
// setHours(hours);
// setHours(hours,minutes);
// setHours(hours, minutes, seconds);
// setHours(hours, minutes, seconds, ms);

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getHours()); // 15
a.setHours(10);
console.log(a.getHours()); // 10

setMilliseconds() method sets the milliseconds of the date.

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getMilliseconds()); // 10
a.setMilliseconds(256);
console.log(a.getMilliseconds()); // 256

setMinutes() method sets the minutes of the date.

// we have different setMinutes method like
// setMinutes(minutes);
// setMinutes(minutes, seconds);
// setMinutes(minutes, seconds, ms);

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getMinutes()); // 13
a.setMinutes(20);
console.log(a.getMinutes()); // 20

setMonth() method sets the month of the date.

// we have different setMonth method like
// setMonth(month);
// setMonth(month, day);

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getMonth()); // 2
a.setMonth(8);
console.log(a.getMonth()); // 8

setSeconds() method sets the seconds of the date.

// we have different setSeconds method like
// setSeconds(seconds);
// setSeconds(seconds, ms);

const a = new Date("March 22, 2023 15:13:20:10");
console.log(a.getSeconds()); // 20
a.setSeconds(26);
console.log(a.getSeconds()); // 26

This is just a short introduction to javascript date Object. if you want to know more about javascript’s Date object then check out these docs.

• Mdn Web Docs
• W3school

Thank You!