This happened to me as well. After switching servers inside of a building i spawned into the same room all the doors closed. I tried to open all the doors but none would open (not even giving me the option to open them). Switching the server resolved the problem however.

I've sat still and let the zombie hit me just to i could get a good hit on him with my hammer. After i died without even hitting the zombie it was obviously a bad decision.

I support the idea of a 4 hour day/night cycle, however, if you want to keep the cycle as is, i suggest you do set some servers to the opposite time as the others.