Which is exactly what I did...I edited the group to September 1st and I am still getting August 1st.  There doesn't seem to be a way to remove the history without deleting the group.  I tried every option under Edit Group and I still get the pop up...."add to my reminders list" - still get the pop up, "do not remind me" - still get the pop up, "automate transaction entry" with "09/01/2018" as the "next date" and still get the pop up...