If it’s a question that can be quickly answered, ask it just before noon EST. Lots of flutherers check in at lunchtime, but the exchanges need to be not too time consuming.
For longer, more thoughtful responses, ask late afternoon or early evening. That’ll catch people when they’re under less time pressure. For silly, loopy, playful stuff, ask late at night when all us fuddy-duddies have sought the refuge of our comfy beds.