Maybe, but those are all pictures of Shadowmoon valley which, predictably, is bathed in eternal night, so... it's probably not the best metric.
“Do not lose time on daily trivialities. Do not dwell on petty detail. For all of these things melt away and drift apart within the obscure traffic of time. Live well and live broadly. You are alive and living now. Now is the envy of all of the dead.” ~ Emily3, World of Tomorrow
Shadowmoon Valley as the name implies, is always in the shadow, meaning it's always nighttime. We haven't seen any pictures of other zones in a night cycle, though that could be because you can take better screens in the daytime.