This takes place during the week of Thanksgiving in November. Science teacher Wilma tells Coach Mellor that Adam Goldberg couldn't come to the alumni game because Terminator 2 just came out. Terminator 2 came out on July 3, 1991, four months earlier.
Adam says he can't turn up as Terminator 2 just came out (1991) yet CB has a furby in his house (seen behind Lainey) which came out in 1998.
When the teachers are speaking about Friendsgiving in the cafeteria, you can clearly see that Johnny Atkins was supposed part of the group, as he is standing next to Lainey.