Board Thread:Naruto Discussions/@comment-25075327-20140618023513/@comment-24891154-20140619020432

Omnibender wrote: We use the Nine-Tails Attack on Konoha as the defining moment from which events are dated. And the villages began about sixty five years prior to current time, the story we got after Itachi died went further in the past than the foundation of the villages. Sage is much older than 500, as Shima and Fukasaku, who are about 800 years, thought the Sage was a myth.

There isn't really any good reason to use the Nine-Tails Attack (and Naruto's birth) as the reference point for years. Many of the more important and worldly significant events in the Naruto canon took place before he was born, including nearly a millennia of chaos. Not that many things happened throughout the 16-17 years of Naruto's life that can be broken down and compared by years; you'd have to start looking at it by months to make a distinction, as the series would only be covering years 12 and 16. And negative numbers just aren't that fun.