Currently the Join Date (in GroupMember) be set to the date the contact was added to the group in iMIS (either via Workbook Converter, or via manually adding the member to the group in iMIS). I would be more accurate if the Join Date was set to the Effective Date of the first term added to that group, for the contact. For example, if we run a data migration today, every contact’s Join Date for every group is set to today. This of course is not accurate, since basically every membership imported would have an effective date prior to today. Same thing with manual data entry… if I’m entering a group membership today (1/11/16) for someone who actually joined on 1/5/16, shouldn’t his Join Date be set to 1/5, rather than 1/11?