Interesting question considering there are members around the world. Just taking the U.S. & Canada I venture a guess that most of the members are in the Eastern & Central Time Zones.
8 PM. Central would be comfortable for those in the Eastern and Mountain time zones but may be too early for the Left Coast (6 PM. Dinner Time!)
And any later Pacific time would be us Right Coasters Bed Time!!
Can't please all the people as the old saw goes!