Can anyone provide more indepth info on the Calculate feature in Portfolio?

[kovame01]

We release at the epic level, so our Initiative and Theme scheduling is based upon the releases set on the underlying Epics.  In Portfolio, the Initiative is showing multiple releases even though in Jira only one release is applied to that Initiative.  I believe that Portfilio assigns the earliest release from the underlying Epics (as the start date) and the latest release (as the end date) to display in the timeline.  Looking to validate this and also gain more insight on this feature.