Depends on how obsessive you are about clarity. I've made apple cider and drank it after only a month in primary. It was still a little cloudy but otherwise fine. I also have ciders that I've aged for 1/2/3 years, which have gotten crystal clear and taken on an even more wonderful flavor with time.

Some years, apple harvests where I live are good, and other years not so great. Not so great apples = not so great cider = benefits more from aging.