This is something I've been messing around with since Son of Neptune
came out and there was a lot of head scratching done about Riordan's numbers game regarding when Jason and Percy went missing. So I decided to be a nerd a finish it up this week. I posted a rough draft on tumblr last night and went back to finalize it up and reformat it before posting it here.
I tried to be as accurate as possible, but there's probably a 1-2 year error on anything that isn't specifically
stated with a year date in canon which wasn't much, to tell you the truth. I based most of the PJO events on Percy's birthday since it was one of the few dates we actually had in canon and to get his year date, I subtracted 16 from the year The Last Olympian
was published (2009) to get his birthdate at August 18, 1993. Everything else was based largely on what was found in canon, but some of that is still contradictory and up to interpretation.
Feel free to ask questions about how I decided on certain dates or argue with me about stuff on the timeline. I love to nerd out about this stuff. I'll probably update the timeline as more information comes out.( Percy Jackson and the Olympians/Heroes of Olympus series timeline )