As I was looking for a simple Stopwatch implementation in JS, I found this code <http://codepen.io/_Billy_Brown/pen/dbJeh/>
The problem is that it's not working fine, the clock go way too fast. I got 30 seconds on the screen when i got only 23 seconds on my watch.
And I don't understand why. The timer function is called every millisecond and should be updating the time correctly.

```
setInterval(this.timer, 1);

```

Is the problem coming from the browser or from the JS code.

Thanks in advance.