The Average, Max and Total response time(s) are calculated in the requests dashboard as shown in the screenshot attached
There is no average/total or max time being calculated when request comes in with current time.
Foglight calculates how much time it takes to response back that is called as complete cycle of a request.
To find the response time browse to FMS console | script console and look for “JAVAEEAppServerRequestType” instance for the complete request cycle details.