Anything over ten minutes is compressed, but that is not a bad thing.
Let the story be your guide. You could have a story that covers ten years in ten minutes and it could feel natural and yet 1 hour might feel rushed. It really all depends on the story you are telling.
I think the key thing to keep in mind with a short is to focus on a smaller/more intimate story and not just try and jam a feature length idea into a short.
It seems like most short films have a very short time frame, though... I haven't seen much short films that have pulled off anything well over a day or two... then again, I see that it's kind of hard to cover a long period of time. I wonder if it's possible to do it well, though.