It was morning, as at the time when the sun was about to rise. Though to the Arshbon, the absence of the sun had always been a normal thing, along with a difficult process of differentiating day from night.
Due to the amount of time spent in such conditions, they have been able to adapt and roughly make an estimate differentiating the day from night through the colour texture of the tree branches above, clouding the sun from them.
The point is, in a way the Arshbon can tell the difference between day and night. They are also not unfamiliar with the effect of the sun as they could just as easily get that by going to the shores where the sun is freely able to shine down without any disturbance from the trees.
After having an eventful day yesterday, Karina the female goblin elder clocked out late, and thus she ended up sleeping in late.