The Ceremony of Twelves is one of the Community's annual Ceremonies and is when the Twelves get their Assignments. Additionally, this is considered the last and most important Ceremony, as there are no more ceremonies following this Ceremony and age becomes unimportant, as noted by several members of the Community. Since this is the final ceremony, it represents a rite of passage into adulthood.
The Ceremony takes place in the month of December and follows the Ceremony of Elevens. The Elevens are then called up to receive their Assignments in a predesignated order. However, as evidenced by Jonas receiving the Assignment of Receiver of Memory, there are some exceptions to the order. After the Ceremony, the Twelves begin the training for their Assignment and their adult life.