estimate start time for log fragments

[kirk-microsoft]

trafficstars

In cases where the toolkit is offered log fragment, calculate a sensible start time. The calculations routinely assume that the logs start at 0.00 seconds which is not true in this case.

The hard question is, what defines a log fragment from a complete log.. IOWs how far from 0.00 seconds do we need to be before we estimate a start time.