I suspect this is an issue with the qmf code using the underlying qpid::sys:AbsTime class representation directly and assuming it is a since the 1970 epoch.
This is not not the case - as documented in cpp/src/qpid/sys/Time.h the value is nanosecs since an unknown base. Accidentally it is probably since 1/1/970 on unix systems, but on Windows I'd bet the epoch is different.
This class was never intended to represent calendar time and so there is no facility to convert it directly.
I guess the quick fix is to shift the epoch base of the windows code when converting AbsTime to Duration since that is the only way to gain access to the internal nanosec from epoch value.
A better way would be to introduce a calendar date to AbsTime constructor so that you can specify the epoch base when you convert to Duration (negative values of AbsTime are perfectly meaningful for this class).