Internet Browse Time in the Fortianalyzer.

[cyber999]

How I do in the Fortianalyzer for the chart Top User Browsing Time tell the exact amount of time that someone spends viewing site once it is open?

In the reports show users with more than one hour on facebook being that the site is blocked.

[chall_FTNT]

It sounds like you believe your Browse Time report is inaccurate.  I would recommend opening a support ticket.  To analyze the browse time calculations, it would be necessary to review webfilter & traffic logs.