One Night at Jeffy's was an SML and FNaF fan game, which was created by janmaar03. The game was about you being in the sml studio. There were three games made and released, which were One night at Jeffy's, One night at Jeffy's 2, and One week at Jeffy's (or One night at Jeffy's 3), there was even a fourth game planned, but the creator deleted all of his games, even the ones that weren't in the one night at Jeffy's series. One night at Jeffy's, One night at Jeffy's 2 and One week at Jeffy's, have been partly found by old youtube videos, one night at Jeffy's also got a fan remake.
One night at Jeffy's: found
One night at Jeffy's 2: found
One week at Jeffy's: found
the forth onaj game: unconfirmed if any work has been done
update: I found the dead link to the 2nd game
update #2: I tried to use the dead link of the 2nd game on the Wayback machine, and it didn't go so well
update #3: I did the same thing again but with janmaar05's account, and I got the same results
update #4: all of the games are back on game jolt thank all of you for searching, we had a good run
update #5: the games are lost once again
update #6: new editor here to this page, the games are actually reuploaded by the creator himself