JavaScript Date parse() Method

The JavaScript Date parse() Method is used to know the exact number of milliseconds that have passed since midnight, January 1, 1970, till the date we provide.

Syntax:

Date.parse(datestring);

Parameters: This method accepts a single parameter:

• datestring: This parameter holds the date as a string.

Return Values: It returns an integer value representing the number of a millisecond between midnight January 1, 1970, and the date provided. If by any means, the machine can’t recognize the string or the input string is invalid, it will return “NaN” instead of an integer.

Example 1:

javascript

// Taking a date string as input.
let date = "February 18, 2018 12:30 PM";

// Calling parse function on input date string.
let msec = Date.parse(date);
console.log(msec);

Output:

1518937200000

Example 2: If the input string of date is not correct, it returns NaN i.e, not a number. 

javascript

// Taking wrong date string as input.
let date = "February 48, 2018 12:30 PM";

// calling parse function.
let msec = Date.parse(date);
console.log(msec);

Output:

NaN

Example 3: If the input string of the date is correct, it returns the difference between the date provided and January 1, 1970. 

javascript

// Taking wrong date string as input.
let date = "June 22, 2012";

// Calling parse function.
let msec = Date.parse(date);
console.log(msec);

Output:

1340303400000

Note: Once we get the millisecond count between two dates, we can easily find the number of hours, days, months, years, etc by simple maths calculation.

Supported Browsers: The browsers supported by the JavaScript Date parse() method are listed below: 

• Google Chrome 1 and above
• Internet Explorer 3  and above
• Mozilla Firefox 1 and above
• Opera 3 and above
• Safari 1 and above

We have a complete list of Javascript Date Objects, to check those please go through this Javascript Date Object Complete reference article.