Well, if the tank had fish in it, I would ALWAYS move new fish into it in the morning....and then WATCH for problems! Too many times, I've moved fish late in the day and then didn't have time to watch them properly, and couldn't intercede when problems erupted.
For an empy tank, I would STILL move the fish earlier in the day, to allow it "to get the lay of the land" before lights out....less chance of it bumping around at night, and less prone to jumping out.
I knew an aquarist who always fed fish minutes after moving them - I always waited until the next day "to allow the fish to become accustomed to the tank". He had generally better results, so I do that now myself.
Jay