It seems to me that if your moral code suddenly stops working because of a change in circumstances (other than something like the zombie apocalypse), then you should get a better moral code. Furthermore if you stop being a good person as soon as your death grows near, then I have my doubts as to whether you were ever a good person.

Now of course that's all philosophical. Psychologically, it does seem that people change their behavior when they know they're going to die and they stop doing things like considering the consequences of their actions.

The thing about that is (and someone correct me if the science says otherwise) I don't think that you'd have the same experience of flipping out and not considering consequences if you had time to prepare. Now some people probably couldn't or wouldn't handle it and would end up doing some shitty things. If you prepared yourself for it though, I think it would be a fantastic chance to get your affairs in order and to make sure that you're ready when the time comes.

I think what it really comes down to is personal preference and personal mental state/personality. Me, I'd love to know. College seems smart now, but if I found out I was going to die next year I'd want to drop out and make the most of the little time I had left. On the other side of the spectrum if I found out that I was going to die at 105, then plans wouldn't change much. I'd love to be able to plan for my demise though, to come to terms with it, make peace with it, and ultimately make sure that I have a good death in the classic Greek sense. More generally, I think it would help me with life planning immensely if I knew where the end-point was.

All that's me though. I do think that many people would be better off not knowing.