The Institution you are applying to be Campus Ambassador for. i.e. University of Adelaide, Dublin Institute of Technology etc.
i.e. Mechanical Engineering, Modern Languages etc.
i.e. final year, 2nd year etc.
Campus Ambassadors can decide when to start and finish their promotion.
We would suggest you chose a minimum 6 week period. Many CAs chose to continue their work for the full academic year, or for a single term.