JavaScript Date

The Javascript Date object in JavaScript is used to represent a moment in time. This time value is since 1 January 1970 UTC (Coordinated Universal Time). We can create a date using the Date object by calling the new Date() constructor as shown in the below syntax.

Syntax:

new Date();
new Date(value);
new Date(dateString);
new Date(year, month, day, hours, minutes, seconds, milliseconds);

Parameters: All of the parameters as shown in the above syntax are described below: 

• value: This value is the number of milliseconds since January 1, 1970, 00:00:00 UTC.
• dateString: This represents a date format.
• year: This is represented by integer values ranging from the years 1900 to 1999.
• month: This is represented by integer values ranging from 0 for January to 11 for December.
• day: This is an optional parameter. This is represented by an integer value for the day of the month.
• hours: This is optional. This is represented by an integer value for the hour of the day.
• minutes: This is optional. This is represented by an integer value for the minute of a time.
• seconds: This is optional. This is represented by an integer value for the second of a time.
• milliseconds: This is optional. This is represented by an integer value for the millisecond of a time.

Return Values: It returns the present date and time if nothing as the parameter is given otherwise it returns the date format and time in which the parameter is given.

Let’s see JavaScript programs on the Date object. 

Example 1: If nothing as the parameter is given, it returns the present date and time. 

javascript

// If nothing as parameter is given,
// it represent the present date and time.
let A = new Date();

// Printing present date and time.
console.log(A);

Output:

Wed Mar 21 2018 20:44:40 GMT+0530 (India Standard Time)

Example 2: When an integer value is passed as the parameter then it gives the number of milliseconds since January 1, 1970, 00:00:00 UTC. 

javascript

// Parameter as integer value give the number of
// milliseconds since January 1, 1970, 00:00:00 UTC.
let A = new Date(32549);

console.log(A);

Output:

Thu Jan 01 1970 05:30:32 GMT+0530 (India Standard Time)

Example 3: When a date String is passed as the parameter then it returns the same as the parameter including the day name. 

javascript

// When any dataString is given as the parameter
// then it return the same as the parameter
// including day name.
let A = new Date('June 22, 1985 07:19:35');

console.log(A);

Output:

Sat Jun 22 1985 07:19:35 GMT+0530 (India Standard Time)

Example 4: When some numbers are passed as parameters then they are considered as year, month, day, hours, minutes, seconds, and milliseconds respectively. 

javascript

// When some numbers are taken as the parameter
// then they are considered as year, month, day,
// hours, minutes, seconds, milliseconds
// respectively.
let A = new Date(1996, 10, 13, 5, 30, 22);

console.log(A);

Output:

Wed Nov 13 1996 05:30:22 GMT+0530 (India Standard Time)

Errors and Exceptions: Open your console to check these errors. 

Example 1: A valid integer variable should be passed as the parameter, otherwise it throws an error.

javascript

// Any integer number should be taken
// as the parameter not any name.
let A = new Date(gfg);

console.log(A);

Output:

Error: gfg is not defined

Example 2: It throws an error if a complex number is passed as a parameter. 

javascript

// Any integer number should be take as
// the parameter not any other number
// e.g- complex number.
let A = new Date(1 + 5i);

console.log(A);

Output:

Error: Invalid or unexpected token

Example 3: If an invalid date string is passed to the constructor, it throws an error. 

javascript

// Any integer number should be taken
//  as the dateString not word.
let A = new Date("geeksforgeeks");

console.log(A);

Output:

Invalid Date

Application: It has many applications such as getting the exact current date and time. Below program prints the current date and time using the Date() object. 

javascript

// If nothing as parameter is given, it
// represent the present date and time.
let A = new Date();

// Printing present date and time.
console.log(A);

Output:

Wed Mar 21 2018 20:44:40 GMT+0530 (India Standard Time)

We have a complete list of Javascript Date object methods, to check those please go through this JavaScript Date Object Complete Reference article.

Supported Browsers: The browsers supported by JavaScript Date are listed below: 

• Google Chrome 1 and above
• Edge 12 and above
• Firefox 1 and above
• Opera 3 and above
• Safari 1 and above