The best times for all contributors.
One of the least obvious things about a project the size of WordPress is to be able to find a timing for contribution activities that works best for as many contributors as possible. Or that works for the contributors who participate in those activities.
Why is it so complicated?
Well, simply because all the contributors to the WordPress project are distributed around the world, covering all continents and dozens of time zones.
In this situation we all have to make concessions. Some people will decide to participate in meetings at late hours, while others will do so when they wake up.