How to Get a Timestamp in JavaScript?

John Au-Yeung - Mar 22 '21 - - Dev Community

Check out my books on Amazon at https://www.amazon.com/John-Au-Yeung/e/B08FT5NT62

Subscribe to my email list now at http://jauyeung.net/subscribe/

A UNIX timestamp is the number of seconds since January 1, 1970 midnight UTC.

It’s often used so that we can do calculations with time easily.

In this article, we’ll look at how to get the UNIX timestamp from a date object in JavaScript.

The + Operator

We can use the + operator to convert the date object right to a UNIX timestamp.

For instance, we can write:

+new Date()
Enter fullscreen mode Exit fullscreen mode

The + operator before the date object triggers the valueOf method in the Date object to return the timestamp as a number.

The getTime Method

We can call getTime to do the same thing.

For instance, we can write:

new Date().getTime()
Enter fullscreen mode Exit fullscreen mode

to return the UNIX timestamp of a date.

Date.now Method

Date.now is a static method of the Date constructor that lets us get the current date-times timestamp.

For instance, we can write:

Date.now()
Enter fullscreen mode Exit fullscreen mode

The timestamp is returned in milliseconds, so we have to divide it by 1000 and round it to get the timestamp in seconds.

To do that, we write:

Math.floor(Date.now() / 1000)
Enter fullscreen mode Exit fullscreen mode

Math.floor rounds the number down to the nearest integer.

We can also round it with Math.round by writing:

Math.round(new Date().getTime() / 1000);
Enter fullscreen mode Exit fullscreen mode

Number Function

The Number function is a global function that lets us convert a non-number object or primitive value to a number.

And we can use it to convert a date to a timestamp.

To do that, we write:

Number(new Date())
Enter fullscreen mode Exit fullscreen mode

Then we get the timestamp in seconds returned since it triggers the valueOf method of the Date instance like the + operator.

Lodash _.now Method

Lodash also has a now method that returns the current timestamp.

To use it, we write:

_.now();
Enter fullscreen mode Exit fullscreen mode

It’ll also return the current date’s timestamp.

Conclusion

There’re many ways to get the timestamp of the current date and time or the date-time that we want with JavaScript.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .