QaF has a completely incoherent timeline, especially after season 1. (HOW long is Melanie pregnant for, exactly? XD) But we know Brian's birthday is immediately before (day before? that night? week before?) Justin's prom. So you can look at the day most schools do prom, and you'd know Brian's brithday is around then. So basically it means this is the time of year his birthday was... which makes him a Gemini. XD;; Makes.... a LOT of sense. (Sorry, I'm into astrology. >_>;;) We have no information on when anyone else's birthdays are. Michael is... 2 months older than Brian? Maybe someone else remembers what he said...?