I am trying to get the time that user spent in a page with moment.js but it returns the wrong value.

Code:

```
dateStart: any;

ngOnInit() {
  this.dateStart = moment(); // current time
}

// when user post data before being redirect
moment(moment(this.dateStart).diff(moment())).format("hh:mm:ss");

```

The code above supposed to return for instance `00:00:04` which means user was in this page for `4 seconds`. but I got something like this `06:59:55`

Any ideas?