Okay, it's safe to say that UbiSoft keeping Sam Fisher "forever young" messes with the potential timeline, but I'm trying to wrap my head around some of the dates. I don't have the full timeline I worked up here, but here's some basics....
Honorably discharged in 1996 from US Navy. Aside from the old "Splinter Cell Bible" saying he was enlisted rank and now they say he was an officer, that it's later said that Sam was "recently retired" in 2004. Now, presuming Sam has a military pension, that should mean 20 years of service (1976). Born 1957, that would make him 19 when he joined, BUT if he finished the US Naval Academy, he would really be around 22 (presuming 4 years of post high school education). Perhaps military people (particularly officers) can qualify for an "early retirement" at less than 20 years, but it's also possible "retired" means he just chose to stop being in the Navy.
Still, what's really hard to figure out is that if Sam was supposed to be a Navy Seal, that's 6 years of his life that's hard to account for...especially since it seems like he was doing field work for the CIA before the documented time he has as a SEAL. There's nothing saying he couldn't have done both...I believe military personal specializing in certain fields (particularly intelligence) get pulled into work for the alphabet agencies, but as a SEAL is constantly having to recertify in many areas of their training, I find it hard to believe that Sam could have worked excusively for the CIA in the field for very long before having to return to a base/stateside for mandatory recertification and training.
Anyone have some better insight on how Sam Fisher's "career" played out?