I believe this idea got started when most orchids were grown in greenhouses. I wouldn't recommend watering a greenhouse late in the day. Especially watered from overhead. I normally try to water in morning cause it gets me going and helps wake me up. Something to do while sipping coffee. But If I have to go somewhere or just forget, I water all the plants (except mounts that get dunked) at night. I have fans blowing as well. Remember, lots of orchids don't like misting or wet leaves, so you'd want to keep them dry anyways.
Mistking
Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids.