The Databooks Don't Do Birthdays
NOTE: Red links are my own posts, blue links are sources written by others.
I first stumbled across this issue when attempting to construct a timeline for Itachi Uchiha. As a reference, I used a timeline by Seelentau on the Naruto Wiki (which is probably the most accurate Naruto timeline on the internet). However, when comparing the timeline to the manga and Databooks, I noticed that Itachi doesn't age up according to canon events - and by extension, neither does Sasuke. Sasuke is 12 when he graduates, has a birthday in July, and somehow during the 3rd round of the Chunin Exams (which takes place in August), he is still 12.
Now, to confirm a long-time suspicion of mine (which I already teased in a previous post) I looked up character ages and birthdays today as depicted in the Naruto Databooks. I noted them down and compared them and realized this:
You cannot base any Naruto timeline events on character ages.
The reason for that is that the Databooks don't age up characters individually or in accordance with their birthdays but instead uniformly, using Naruto's age as a point of reference. You can see this more clearly in the sheet below.
Here's a bit more context.
Unless each databook was released during the in-universe Ninja Academy graduation months, the age progression as depicted in the Databooks is absolutely impossible. And in fact, they were not released during that in-universe time period.
Naruto's class most likely graduates in March in accordance with the Japanese school year as strongly suggested in Chapter #11 of the Manga. Furthermore, this matches up with the time skip that takes place between September/October (when Naruto's classmates are 13) and March/April (when Naruto's classmates are 15) making a near-perfect 2.5 gap (more on that later).
Everybody in Naruto's class is 12 at this point in time.
The Chunin Exams commence on July 1st, with the 3rd and final round taking place somewhere between August 1st and August 6th depending on how you do the calculations, but it's approximately one month later. Rin no Sho covers chapters #1-119.
Chouji, Kiba, and Sasuke both had a birthday between March and August, yet remain 12 years old like the rest of the cast.
Then Naruto and Jiraiya search for Tsunade for at least a month and after Sasuke's defection and an additional 3-month time skip, we get another Databook.
In this time period, only Temari, Kakashi, Ino, Naruto, Orochimaru, Asuma, Jiraiya, Lee, and Shizune definitively celebrated a birthday, yet the entire cast ages up by one year.
Then a approximately 2.25-year time skip rolls around which, if we do the calculations (including that Team 7 only has six months left for rescuing Sasuke), must take place 2 years later in March or April, assuming the time skip occurred after September or October. We see Konohamaru as a freshly graduated Genin, so this makes perfect sense.
An unknown amount of time passed before the Third Databook was finally released, which covers the events up until Itachi's death, and the truth behind the Uchiha Genocide is uncovered.
The characters have now all uniformly aged up by three years.
The only Databook that falls out of line with this practice is the Fourth Databook. I have that one covered in a sequel to this post.
