As a user, I would like to be able to start a sprint with a start date specified in the past.

This was a problem for us because we neglected to start the sprint in GreenHopper when the sprint actually started, so I wanted to retrospectively start it. (This happened because we did the sprint planning and acceptance whilst the previous sprint was ongoing, and GreenHopper won't allow us to specify the next sprint without ending the current one. By the time the next sprint started, we forgot to start it in GreenHopper. (We're new to using GreenHopper in our scrum process ) I believe multiple sprints is a feature that is being planned for a future GreenHopper release?)