No exact details about these concerts have been revealed yet, but it's now clear that the group will be holding two lives on the same day on new year's eve 12/31.
Supposedly the 9th live will be held in the noon and afternoon with the adult members appearing at the Countdown Live towards the evening.
Members of the Fan-sama club will be able to preorder tickets for the 9th live on 11/16.
Source: Idoling!!! Official Website