Deprecated! This metric is not in use anymore, use Session Duration instead.
How long time did the user spent during the entire session (or visit) in seconds.
IMPORTANT: Time on site can only be calculated if the user visits a second page and the last page view is not calculated. So, if a user visits one page for 5 min, a second page for 20 min and leaves your site, the time on site will be 5 minutes.