I am sure there are legal reasons but if I had to set up a remote company I would probably try to restrict the timezones. My current company has dev teams in South America and India. They are all good people but dealing with India [13 hours) is a big pain because somebody has to make calls during his personal time instead of work time. It’s a real burden. And in my view you absolutely have to make direct calls from time to time. You can’t resolve all issues with asynchronous communication.