In any given time zone, at what hour are the most people asleep (my guess is 3 AM to 4 AM, but is there a real statistic)?

Time zones do not extend all the way around the world. The most people are asleep when the highest population is asleep without wasting body counts by being in the ocean. So the time zone that includes the coast of China and those just to the west is a good candidate. And sleep time varies depending on the season. If we say that most people wake at 6 am local time and sleep for 8 hours, then a span 1/3 of the world wide (8 hours) would have people sleeping and either the coast or the next one west would probably have the most people. Earlier would include the ocean in the night area. All of China is on +8 hours GMT, so at 2200 hours GMT it is 0600 in China and I would pick 2200 GMT as the time when the maximum number of people are asleep

https://www.reddit.com/r/theydidthemath/comments/5qt6ku/request_at_what_time_and_day_of_week_are_the_most/