How do you get a timestamp in JavaScript?

Question

Something similar to Unix's timestamp, that is a single number that represents the current time and date. Either as a number or a string.

Answer 1

Short & Snazzy:

+ new Date() 

A unary operator like plus triggers the valueOf method in the Date object and it returns the timestamp (without any alteration).

Details:

On almost all current browsers you can use Date.now() to get the UTC timestamp in milliseconds; a notable exception to this is IE8 and earlier (see compatibility table).

You can easily make a shim for this, though:

if (!Date.now) {     Date.now = function() { return new Date().getTime(); } } 

To get the timestamp in seconds, you can use:

Math.floor(Date.now() / 1000) 

Or alternatively you could use:

Date.now() / 1000 | 0 

Which should be slightly faster, but also less readable.
(also see this answer or this with further explaination to bitwise operators).

I would recommend using Date.now() (with compatibility shim). It's slightly better because it's shorter & doesn't create a new Date object. However, if you don't want a shim & maximum compatibility, you could use the "old" method to get the timestamp in milliseconds:

new Date().getTime() 

Which you can then convert to seconds like this:

Math.round(new Date().getTime()/1000) 

And you can also use the valueOf method which we showed above:

new Date().valueOf() 

Timestamp in Milliseconds

var timeStampInMs = window.performance && window.performance.now && window.performance.timing && window.performance.timing.navigationStart ? window.performance.now() + window.performance.timing.navigationStart : Date.now();  console.log(timeStampInMs, Date.now());

Answer 2

I like this, because it is small:

+new Date 

I also like this, because it is just as short and is compatible with modern browsers, and over 500 people voted that it is better:

Date.now()