Norman has some pretty lengthy gaps inbetween events, though I have only unlocked 3 scenes with him in the gallery so I may have missed some. Only one of those scenes is Eric and Norman and it happened after day 60. The two events that you should watch out for are on the weekend (sorry I can't remember exact weekends) but he will come into your room invite you to town, and then later you meet up with him in the kitchen and will ask you if you are into boxing (say yes)