At what times by Greenwich Mean Time are the greatest and fewest number of people on Earth likely to be asleep?

This would probably coincide with the sleeping/waking patterns of the countries with the largest populations. All of China is in UTC+8, and all of India is in UTC+5:30. When it is noon in India, it is 2:30 in the afternoon in all of China. Maybe waking hours from two hours before that until two hours after that would be a reasonable guess for peak wakefulness. That would be 4:30 GMT until 6:30 GMT. But sleeping is much harder to even estimate, without a lot more information about typical sleeping times.

https://www.timeanddate.com/time/map/

This Vsauce video, which inspired the question, claims that most people are asleep at 3pm LA time. This equates to 11pm GMT. https://youtube.com/shorts/DtAtNp5NL1s?si=g6JMkpS9hUFVqOkg