JavaScript Date parse() Method
The JavaScript Date parse() method parses a date string and returns the number of milliseconds between the date string and midnight of January 1, 1970, UTC. If the argument is an invalid date string, it returns NaN (Not a Number).
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 milliseconds 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: Parsing Date String to Milliseconds
The code takes a date string “February 18, 2018, 12:30 PM” and parses it using the Date.parse() method, which returns the number of milliseconds since January 1, 1970. The result is logged to the console.
// 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
1518957000000
Example 2: Parsing Invalid Date String
The code attempts to parse an invalid date string “February 48, 2018 12:30 PM” using the Date.parse() method. Since the date is invalid, the method returns NaN (Not a Number), which is logged to the console.
// 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
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:
JavaScript Date parse() Method- FAQs
What does the Date.parse() method do in JavaScript?
The Date.parse() method parses a string representation of a date and returns the number of milliseconds since January 1, 1970, 00:00:00 UTC (the Unix Epoch).
What date formats are supported by Date.parse()?
Date.parse() supports ISO 8601 date formats (e.g., “YYYY-MM-DDTHH:mm.sssZ”). It may also support RFC 2822/822 formatted strings, depending on the JavaScript environment.
Can Date.parse() handle fractional seconds?
Yes, Date.parse() can handle fractional seconds in the ISO 8601 format (e.g., “YYYY-MM-DDTHH:mm.sssZ”).
What is the recommended format for Date.parse()?
The recommended format for Date.parse() is ISO 8601 (e.g., “YYYY-MM-DDTHH:mm.sssZ”) for compatibility and predictability.
What are the limitations of Date.parse()?
The limitations include:
- Inconsistent parsing of non-ISO date strings across different browsers.
- Limited handling of date strings that do not conform to ISO 8601 format.
We have a complete list of Javascript Date Objects, to check those please go through this Javascript Date Object Complete reference article.
