I'm not sure exactly how long it has been down, but at least 6 or 7 hours as far as I can tell without trying to log in constantly. It was a significant number of hours yesterday as well (5+ I think). While it's not the end of the world, it does make it tough to calculate when to make sure moves that were based on a time when I knew certain research would end, such as advanced orbitals. Sure, I can build them whenever the server comes back, but now I'm not sure exactly what time that will be and maybe I'm not around to take those actions I had planned. ./shrug, I guess.

More than anything my concern is over lack of information, though of course I wish I was able to log in today. This is really a bigger issue than the server being down in that we are often left to our own devices to figure out how the game systems work. For example, the explanation over how trade works still left a lot to be desired and I'm not sure if I receive any benefit from someone trading with me (I can't see any net gain). I can list many other examples if necessary. Not exactly on topic, but I felt it goes hand in hand with the problem behind not knowing if and when the server might come back up.