Hi Craig
Sadly no.
We report on Training (classroom) time and the Face-to-face module invitations are also used in the Calendar appointments and include non-training time such as; welcomes, catering breaks, and for mutliday events would include the overnight time period (and/or weekends).
As the Duration field was often overlooked by those setting up F2F sessions we made the field complusory in our site.
Cheers
Austen