Okay, so we've got two opinions. One that takes place in between FNAF 1 and 3, and one that it takes place in between FNAF 2 (which is a prequel) and FNAF 4 (Also Prequel). Which one should we list down, or should we list both?
Neither. The only thing about SL’s time placement is that it takes place before FFPS. Speculation without definitive confirmation will most likely get removed from an article.
Though I have to admit that I’m not so sure about it taking place between 1 and 3 anymore, since SL seems like the actual catalyst for Michael’s role in undoing his father’s sins. With FFPS’ implication that all the previous night guards (except 4 and possibly 3) were false identities that Michael took, I’d be willing to accept it taking place between 4 and 2, if going by Trica’s theory that the remnant within Ennard that Elizabeth/Baby transferred to Michael turned him back into a completely normal human, because, well... even with Fazbear Entertainment’s absurdity, I doubt even they would hire a rotten corpse, and something has to explain that nervous heartbeat.