Its nice to know that you guys work in positive environments, My boss/company was aware of my plans for law school. I tried to keep it a secret, but the December Lsat was the morning after our Christmas party. When i told my direct supervisor (in confidence) why i would't be drinking/staying late, she told the whole company. (This was December 2003)
I was planning to leave February 2005, and was going to give a month a half notice to replace my job (not a very technical job, but the company has had a tough time recruiting in the past and i wanted to give them enough time.) My first week back, i noticed some different behaviour/policies implemented. Our finance manager advised me to only give two weeks, as they would probably rather have my position vacant than pay me extra. Sure enough, when i gave my two weeks notice, they told me the next day should be my last. I still have them as a reference and they threw me a goodbye party, but if you are counting on that money, look at how they have treated things like this in the past.
All in all, wasn't that bad, as i am now typing this from New Zealand, where i am travelling before school starts.