The "Release Capacity" dialog allows users to enter in a capacity amount. however, the dialog doesn't much help in figuring the hours, days nor weeks. For example, I needed to manually calculate that there are 22 working days in July 2016 by counting only weekdays and excluding weekends. Then I can multiply the 22 days by the number of developers that we have on staff (e.g., 22d x 3 developers = 66d). It would be helpful if the dialog can provide hints such as the number of business days based on the start and end dates of a release.
We currently manage this on a spreadsheet to calculate what the actual FTE is. Basically available hrs in the year less leave less events less innovation days etc... We then look at the teams capacity to work on roadmap items (as you don't want to roadmap support or bugs) ..... so say deduct 20% for teams with high support escalation volumes. We then plug this number into Aha. A long-winded way to say "yes it would be great to not have to calculate this externally".