Disclaimer
This is a possible theory of the timeline and things that have happened within the made up franchise of Freddy Fazbear's Pizza in the game series of Five Nights at Freddy's. This is a possible timeline acquired by researching the lore as best as possible. There is no way this theory is 100% correct, but I'm making it to disprove a few notions. First I'd like to disprove the notion that the fourth game takes place in 1987. Second I also propose that the first game takes place in 1992. These kinds of things are only interesting for me to discuss and as said in no way are they 100% proven. If you dislike the game of Five Nights at Freddy's, I do not care, stop wasting your time clicking on blogs just to say it. On with the show.
WARNING theories and speculation and possible spoilers WARNING
Around this time the restaurant officially opens. This is a rough estimate based on what "Phone Guy" says in the first game, that the restaurant has been open for twenty years.
It was probably around this time, maybe a few years before, that the original owners had to sell the restaurant to a company probably due to a murdered child found outside the restaurant. This child would also end up possessing toys and probably trying to socialize with other children being originally lonely by nature. It was after this incident that the restaurant would reopen.
Around this time the Puppet tried to make friends with a lonely child often picked on by his older brother who more than likely worked at the Pizzaria at the time. The young boy was accidentally hospitalized and killed when his older brother placed him in the mouth of an animatronic. This and other incidents resulting in the deaths of workers probably pushed the company to promote the animatronics rather then the suits more as well as the four characters we all know today, characters that were well known at the time due to the TV show that was following the franchise. Around this time other children were abducted and killed as well so when the new animatronics started appearing, the first spirit turning and possessing the actual Puppet body began taking the spirits and allowing them to possess the animatronics with the child possessing the Golden Freddy suit. This probably spans the time of about a year so the new animatronics and the possession could have taken place in 1984 as well.
Due to the smell of the animatronics and possibly complaints of them acting strange, particularly Foxy due to Foxy seeing dead children bodies and having already been murdered by the Purple Man is probably acting more and more violent. Soon the older animatronics are decommissioned and newer ones show up based on their old toy line, but since the older ones are possessed they continue to roam at night, while the newer ones are probably slowly reprogrammed to ward off security guards. The Purple Man was the nightshift guard and is now working the dayshift due to issues with the animatronics at night. This however allows Purple Man to be caught using the Springtrap suit so he flees and the suit is placed in the older restaurant. Jeremy the night guard eventually ends up in the day shift and is bitten by an animatronic, most likely the Mangle which causes the toy robots to be decommissioned due to them being reprogrammed. This all of course takes place in Five Nights 2, and the date can be proven with Jeremy's check which states the check was written November 12th 1987 which would actually be a Thursday.
After five years of being shut down, the restaurant finally opens back up and the older classic characters return though the restaurant is still in disrepair due to the rumors and the previous issues. Accidentally hiring an old employee by a new name, Mike, who is most likely the Purple Man returned due to the uneasiness the spirits have given him. He even tries to reprogram the animatronics to see which gets him fired, but being convinced the things are dangerous he waits and starts dismantling them since the restaurant closes down again. Soon the ghosts of the four animatronics, and Puppet confront the Purple Man and he hides in the suit he has used for years to torture the children however this suit ends up killing him. This date is taken from the idea that Mike's check was also written on a Thursday like Jeremy's check, and 1992 is a year that November 12th is once again a Thursday. This also goes into the idea that the killer probably subconsciously associates with the number 5, as if this theory holds up, Purple Guy didn't murder the one possessing Golden Freddy, rather he killed the Puppet's original body as well as four others who possessed the original Bonnie, Chica, Freddy, and Foxy as his first five victims, and often kills in groups of five afterwards.
An amusement park of the Fredbear brand has been made as a horror attraction and the suit, thought to be a normal animatronic is brought it, however it functions as both a suit and a robot and unknown to the finder there was a dead body in it. The place burns down after the original animatronics as well as Golden Freddy spirit and the Puppet spirit are liberated clearing up most of the spirits, but even after the establishment burns down the spirit of the Purple Guy or Springtrap lives on. If we assume the game takes place 30 years after the restaurant opens however, the game actually takes place around 2002, which is only ten years after the first game but this is unlikely.
The date November 12th comes up a lot in this game series, and if you believe my theory here, it ends up being a Thursday a lot too. Hmmm odd isn't it? Scott Games went dark right before November 12th.... a particular November 12th that falls on a Thursday.... interesting indeed.