Currently, Bridge doesn't provide a property within a live training for tracking the duration. It seems that Bridge expects the duration of individual sessions within a live training could vary from one to the next. While that does provide flexibility in scheduling, it also seems that if a live training is normally 90 minutes, then it would be beneficial to know that typical duration when scheduling sessions.
With a duration property at the live training level, the author could set the start time, then Bridge could automatically suggest an end time based on the duration property of the live training. The author could still adjust the duration on an individual session as needed.
The lack of a duration on the live training also makes it difficult for Bridge to accurately calculate the time needed to complete programs that include live trainings, until the learner has registered for sessions. With a live training duration property, Bridge could more accurately display the time needed to complete the session when presenting it to the learner in the Learning Library.