At many universities, the tenure evaluation year may actually take most of a year, starting with the soliciting of external evaluation letters (perhaps in the summer, with due dates in the fall), and then proceeding through all the various stages of votes and decisions, from the department on up to the overlords. Although there are exceptions, most of which are terrifying, it's typically the first few decision stages that matter. If you've got positive votes all the way past the dean, the grand vizier, and up to the czar and/or the ruling junta, you're probably going to get some good news in the spring or early summer.
Even so, many tenure candidates are anxious all the way through to the final stages and don't feel comfortable counting on tenure until the final official step. By that point, though, celebrating seems somewhat anti-climactic because of the protracted process and because others considered tenure a done-deal at some earlier stage of the process, so it might be hard to get anyone but your mother and maybe your dog excited about the final final decision.
I remember wanting to know the results on the day of the final final decision, but all those who could actually tell me the result thought I was being weird and in fact had no plans to find out the result. According to them, the results, which would surely be positive, would be announced eventually, so why worry about it? Why?: because it was really really important to me and I wanted to know. I wanted the whole process to be over, officially over.
If you have been through the tenure process (successfully), when did you celebrate (if ever)? Did you celebrate after each intermediate step, did you celebrate only after the decision stage(s) that you considered to be most crucial, or did you wait until the very end? By the very end, did anyone else but you even care?
8 years ago